400401591664 has 20 divisors (see below), whose sum is σ = 775800977256. Its totient is φ = 200194887872.

The previous prime is 400401591641. The next prime is 400401591671. The reversal of 400401591664 is 466195104004.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 218202 + ... + 921094.

Almost surely, 2^400401591664 is an apocalyptic number.

It is an amenable number.

400401591664 is a deficient number, since it is larger than the sum of its proper divisors (375399385592).

400401591664 is a wasteful number, since it uses less digits than its factorization.

400401591664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 738504 (or 738498 counting only the distinct ones).

The product of its (nonzero) digits is 103680, while the sum is 40.

Adding to 400401591664 its reverse (466195104004), we get a palindrome (866596695668).

The spelling of 400401591664 in words is "four hundred billion, four hundred one million, five hundred ninety-one thousand, six hundred sixty-four".