309894490638 has 48 divisors (see below), whose sum is σ = 719567031456. Its totient is φ = 96136476480.

The previous prime is 309894490627. The next prime is 309894490643. The reversal of 309894490638 is 836094498903.

309894490638 is a `hidden beast` number, since 3 + 0 + 9 + 89 + 4 + 490 + 63 + 8 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 10100053 + ... + 10130688.

It is an arithmetic number, because the mean of its divisors is an integer number (14990979822).

Almost surely, 2^309894490638 is an apocalyptic number.

309894490638 is an abundant number, since it is smaller than the sum of its proper divisors (409672540818).

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

309894490638 is a wasteful number, since it uses less digits than its factorization.

309894490638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20230809 (or 20230806 counting only the distinct ones).

The product of its (nonzero) digits is 40310784, while the sum is 63.

The spelling of 309894490638 in words is "three hundred nine billion, eight hundred ninety-four million, four hundred ninety thousand, six hundred thirty-eight".