161801564 has 6 divisors (see below), whose sum is σ = 283152744. Its totient is φ = 80900780.

The previous prime is 161801551. The next prime is 161801569. The reversal of 161801564 is 465108161.

161801564 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×161801564² = 52359492225692192, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 161801564.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161801569) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20225192 + ... + 20225199.

It is an arithmetic number, because the mean of its divisors is an integer number (47192124).

Almost surely, 2^161801564 is an apocalyptic number.

It is an amenable number.

161801564 is a deficient number, since it is larger than the sum of its proper divisors (121351180).

161801564 is a wasteful number, since it uses less digits than its factorization.

161801564 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40450395 (or 40450393 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 32.

The square root of 161801564 is about 12720.1243704612. The cubic root of 161801564 is about 544.9135053376.

The spelling of 161801564 in words is "one hundred sixty-one million, eight hundred one thousand, five hundred sixty-four".