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400400 = 245271113
BaseRepresentation
bin1100001110000010000
3202100020122
41201300100
5100303100
612325412
73255230
oct1416020
9670218
10400400
11253910
12173868
13110330
14a5cc0
157d985
hex61c10

400400 has 120 divisors (see below), whose sum is σ = 1291584. Its totient is φ = 115200.

The previous prime is 400391. The next prime is 400409. The reversal of 400400 is 4004.

Adding to 400400 its reverse (4004), we get a palindrome (404404).

Multipling 400400 by its reverse (4004), we get a square (1603201600 = 400402).

400400 divided by its reverse (4004) gives a square (100 = 102).

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (400391) and next prime (400409).

It is a Harshad number since it is a multiple of its sum of digits (8).

It is a super Niven number, because it is divisible the sum of any subset of its (nonzero) digits.

It is not an unprimeable number, because it can be changed into a prime (400409) by changing a digit.

400400 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 30794 + ... + 30806.

2400400 is an apocalyptic number.

400400 is a gapful number since it is divisible by the number (40) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 400400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (645792).

400400 is an abundant number, since it is smaller than the sum of its proper divisors (891184).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

400400 is a wasteful number, since it uses less digits than its factorization.

400400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 49 (or 38 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 8.

The square root of 400400 is about 632.7716807823. The cubic root of 400400 is about 73.7051820006.

The spelling of 400400 in words is "four hundred thousand, four hundred", and thus it is an iban number.