165638394 has 24 divisors (see below), whose sum is σ = 370461312. Its totient is φ = 53431560.

The previous prime is 165638357. The next prime is 165638411. The reversal of 165638394 is 493836561.

165638394 is a `hidden beast` number, since 1 + 6 + 5 + 638 + 3 + 9 + 4 = 666.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 147864 + ... + 148979.

It is an arithmetic number, because the mean of its divisors is an integer number (15435888).

Almost surely, 2^165638394 is an apocalyptic number.

165638394 is an abundant number, since it is smaller than the sum of its proper divisors (204822918).

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

165638394 is a wasteful number, since it uses less digits than its factorization.

165638394 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 296882 (or 296879 counting only the distinct ones).

The product of its digits is 466560, while the sum is 45.

The square root of 165638394 is about 12870.0580418272. The cubic root of 165638394 is about 549.1871121091.

The spelling of 165638394 in words is "one hundred sixty-five million, six hundred thirty-eight thousand, three hundred ninety-four".