400397947956 has 48 divisors (see below), whose sum is σ = 1099131626880. Its totient is φ = 125615041920.

The previous prime is 400397947949. The next prime is 400397947967. The reversal of 400397947956 is 659749793004.

400397947956 is a `hidden beast` number, since 40 + 0 + 3 + 9 + 79 + 479 + 56 = 666.

It is a junction number, because it is equal to n+sod(n) for n = 400397947893 and 400397947902.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 109039000 + ... + 109042671.

It is an arithmetic number, because the mean of its divisors is an integer number (22898575560).

Almost surely, 2^400397947956 is an apocalyptic number.

It is an amenable number.

400397947956 is an abundant number, since it is smaller than the sum of its proper divisors (698733678924).

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

400397947956 is a wasteful number, since it uses less digits than its factorization.

400397947956 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 218081701 (or 218081693 counting only the distinct ones).

The product of its (nonzero) digits is 51438240, while the sum is 63.

The spelling of 400397947956 in words is "four hundred billion, three hundred ninety-seven million, nine hundred forty-seven thousand, nine hundred fifty-six".