401687638 has 12 divisors (see below), whose sum is σ = 657460908. Its totient is φ = 182542560.

The previous prime is 401687597. The next prime is 401687641. The reversal of 401687638 is 836786104.

It is a super-2 number, since 2×401687638² = 322705917044038088, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 401687594 and 401687603.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 91870 + ... + 96142.

It is an arithmetic number, because the mean of its divisors is an integer number (54788409).

Almost surely, 2^401687638 is an apocalyptic number.

401687638 is a deficient number, since it is larger than the sum of its proper divisors (255773270).

401687638 is an frugal number, since it uses more digits than its factorization.

401687638 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8559 (or 4286 counting only the distinct ones).

The product of its (nonzero) digits is 193536, while the sum is 43.

The square root of 401687638 is about 20042.1465417255. The cubic root of 401687638 is about 737.8410644245.

The spelling of 401687638 in words is "four hundred one million, six hundred eighty-seven thousand, six hundred thirty-eight".