400640697 has 6 divisors (see below), whose sum is σ = 578703242. Its totient is φ = 267093792.

The previous prime is 400640689. The next prime is 400640711. The reversal of 400640697 is 796046004.

400640697 is a `hidden beast` number, since 4 + 0 + 0 + 640 + 6 + 9 + 7 = 666.

It can be written as a sum of positive squares in only one way, i.e., 400640256 + 441 = 20016^2 + 21^2 .

It is not a de Polignac number, because 400640697 - 2³ = 400640689 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (400640687) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 22257808 + ... + 22257825.

Almost surely, 2^400640697 is an apocalyptic number.

It is an amenable number.

400640697 is a deficient number, since it is larger than the sum of its proper divisors (178062545).

400640697 is a wasteful number, since it uses less digits than its factorization.

400640697 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44515639 (or 44515636 counting only the distinct ones).

The product of its (nonzero) digits is 36288, while the sum is 36.

The square root of 400640697 is about 20016.0110161840. The cubic root of 400640697 is about 737.1994811991.

The spelling of 400640697 in words is "four hundred million, six hundred forty thousand, six hundred ninety-seven".