400040720 has 40 divisors (see below), whose sum is σ = 933999000. Its totient is φ = 159344640.

The previous prime is 400040717. The next prime is 400040741. The reversal of 400040720 is 27040004.

It can be written as a sum of positive squares in 4 ways, for example, as 8317456 + 391723264 = 2884^2 + 19792^2 .

It is a tau number, because it is divible by the number of its divisors (40).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8906 + ... + 29654.

It is an arithmetic number, because the mean of its divisors is an integer number (23349975).

Almost surely, 2^400040720 is an apocalyptic number.

400040720 is a gapful number since it is divisible by the number (40) formed by its first and last digit.

It is an amenable number.

400040720 is an abundant number, since it is smaller than the sum of its proper divisors (533958280).

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

400040720 is a wasteful number, since it uses less digits than its factorization.

400040720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21003 (or 20997 counting only the distinct ones).

The product of its (nonzero) digits is 224, while the sum is 17.

The square root of 400040720 is about 20001.0179740932. The cubic root of 400040720 is about 736.8313011735.

Adding to 400040720 its reverse (27040004), we get a palindrome (427080724).

The spelling of 400040720 in words is "four hundred million, forty thousand, seven hundred twenty".