161957004 has 48 divisors (see below), whose sum is σ = 415543296. Its totient is φ = 48686400.

The previous prime is 161956999. The next prime is 161957039. The reversal of 161957004 is 400759161.

It is a super-2 number, since 2×161957004² = 52460142289312032, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (33).

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, 11934 + ... + 21594.

It is an arithmetic number, because the mean of its divisors is an integer number (8657152).

Almost surely, 2^161957004 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 161957004, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (207771648).

161957004 is an abundant number, since it is smaller than the sum of its proper divisors (253586292).

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

161957004 is a wasteful number, since it uses less digits than its factorization.

161957004 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9806 (or 9804 counting only the distinct ones).

The product of its (nonzero) digits is 7560, while the sum is 33.

The square root of 161957004 is about 12726.2329068739. The cubic root of 161957004 is about 545.0879458558.

The spelling of 161957004 in words is "one hundred sixty-one million, nine hundred fifty-seven thousand, four".