400081656 has 64 divisors (see below), whose sum is σ = 1093276800. Its totient is φ = 121258368.

The previous prime is 400081639. The next prime is 400081679. The reversal of 400081656 is 656180004.

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, 11335 + ... + 30473.

It is an arithmetic number, because the mean of its divisors is an integer number (17082450).

Almost surely, 2^400081656 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 400081656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (546638400).

400081656 is an abundant number, since it is smaller than the sum of its proper divisors (693195144).

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

400081656 is a wasteful number, since it uses less digits than its factorization.

400081656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19228 (or 19224 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 30.

The square root of 400081656 is about 20002.0412958278. The cubic root of 400081656 is about 736.8564335295.

The spelling of 400081656 in words is "four hundred million, eighty-one thousand, six hundred fifty-six".