161657724 has 12 divisors (see below), whose sum is σ = 377201384. Its totient is φ = 53885904.

The previous prime is 161657701. The next prime is 161657753. The reversal of 161657724 is 427756161.

It is a tau number, because it is divible by the number of its divisors (12).

It is a super-2 number, since 2×161657724² = 52266439457720352, which contains 22 as substring.

It is a hoax number, since the sum of its digits (39) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6735727 + ... + 6735750.

Almost surely, 2^161657724 is an apocalyptic number.

It is an amenable number.

161657724 is an abundant number, since it is smaller than the sum of its proper divisors (215543660).

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

161657724 is a wasteful number, since it uses less digits than its factorization.

161657724 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13471484 (or 13471482 counting only the distinct ones).

The product of its digits is 70560, while the sum is 39.

The square root of 161657724 is about 12714.4690805397. The cubic root of 161657724 is about 544.7519832142.

It can be divided in two parts, 1616 and 57724, that added together give a triangular number (59340 = T₃₄₄).

The spelling of 161657724 in words is "one hundred sixty-one million, six hundred fifty-seven thousand, seven hundred twenty-four".