400640450 has 96 divisors (see below), whose sum is σ = 897156864. Its totient is φ = 130141440.

The previous prime is 400640447. The next prime is 400640453. The reversal of 400640450 is 54046004.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (400640447) and next prime (400640453).

It is a Harshad number since it is a multiple of its sum of digits (23).

It is not an unprimeable number, because it can be changed into a prime (400640453) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1263692 + ... + 1264008.

It is an arithmetic number, because the mean of its divisors is an integer number (9345384).

Almost surely, 2^400640450 is an apocalyptic number.

400640450 is an abundant number, since it is smaller than the sum of its proper divisors (496516414).

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

400640450 is a wasteful number, since it uses less digits than its factorization.

400640450 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 516 (or 511 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 23.

The square root of 400640450 is about 20016.0048461225. The cubic root of 400640450 is about 737.1993297015.

Adding to 400640450 its reverse (54046004), we get a palindrome (454686454).

The spelling of 400640450 in words is "four hundred million, six hundred forty thousand, four hundred fifty".