400446640 has 40 divisors (see below), whose sum is σ = 1015680528. Its totient is φ = 145616640.

The previous prime is 400446617. The next prime is 400446643. The reversal of 400446640 is 46644004.

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

It is a super-2 number, since 2×400446640² = 320715022974579200, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 400446599 and 400446608.

It is not an unprimeable number, because it can be changed into a prime (400446643) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 226647 + ... + 228406.

Almost surely, 2^400446640 is an apocalyptic number.

400446640 is a gapful number since it is divisible by the number (40) formed by its first and last digit.

It is an amenable number.

400446640 is an abundant number, since it is smaller than the sum of its proper divisors (615233888).

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

400446640 is a wasteful number, since it uses less digits than its factorization.

400446640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 455077 (or 455071 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 28.

The square root of 400446640 is about 20011.1628847501. The cubic root of 400446640 is about 737.0804370242.

The spelling of 400446640 in words is "four hundred million, four hundred forty-six thousand, six hundred forty".