400405900 has 36 divisors (see below), whose sum is σ = 898848720. Its totient is φ = 154638400.

The previous prime is 400405883. The next prime is 400405909. The reversal of 400405900 is 9504004.

It is not an unprimeable number, because it can be changed into a prime (400405909) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 66136 + ... + 71935.

It is an arithmetic number, because the mean of its divisors is an integer number (24968020).

Almost surely, 2^400405900 is an apocalyptic number.

It is an amenable number.

400405900 is an abundant number, since it is smaller than the sum of its proper divisors (498442820).

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

400405900 is a wasteful number, since it uses less digits than its factorization.

400405900 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 138114 (or 138107 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 22.

The square root of 400405900 is about 20010.1449270114. The cubic root of 400405900 is about 737.0554402062.

Adding to 400405900 its reverse (9504004), we get a palindrome (409909904).

The spelling of 400405900 in words is "four hundred million, four hundred five thousand, nine hundred".