400120000 has 140 divisors (see below), whose sum is σ = 1134699280. Its totient is φ = 137088000.

The previous prime is 400119997. The next prime is 400120001. The reversal of 400120000 is 21004.

It is a tau number, because it is divible by the number of its divisors (140).

It is a Harshad number since it is a multiple of its sum of digits (7).

It is not an unprimeable number, because it can be changed into a prime (400120001) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 279286 + ... + 280714.

Almost surely, 2^400120000 is an apocalyptic number.

400120000 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 400120000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (567349640).

400120000 is an abundant number, since it is smaller than the sum of its proper divisors (734579280).

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

400120000 is an equidigital number, since it uses as much as digits as its factorization.

400120000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1468 (or 1443 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 7.

The square root of 400120000 is about 20002.9997750337. Note that the first 3 decimals coincide. The cubic root of 400120000 is about 736.8799729912.

Adding to 400120000 its reverse (21004), we get a palindrome (400141004).

The spelling of 400120000 in words is "four hundred million, one hundred twenty thousand".