161560725 has 12 divisors (see below), whose sum is σ = 267113856. Its totient is φ = 86165680.

The previous prime is 161560723. The next prime is 161560739. The reversal of 161560725 is 527065161.

161560725 = 1773² + 1774² + ... + 1822².

It is not a de Polignac number, because 161560725 - 2¹ = 161560723 is a prime.

It is a super-2 number, since 2×161560725² = 52203735725051250, which contains 22 as substring.

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161560723) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1076997 + ... + 1077146.

It is an arithmetic number, because the mean of its divisors is an integer number (22259488).

Almost surely, 2^161560725 is an apocalyptic number.

161560725 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

161560725 is a deficient number, since it is larger than the sum of its proper divisors (105553131).

161560725 is a wasteful number, since it uses less digits than its factorization.

161560725 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2154156 (or 2154151 counting only the distinct ones).

The product of its (nonzero) digits is 12600, while the sum is 33.

The square root of 161560725 is about 12710.6539957628. The cubic root of 161560725 is about 544.6430061145.

The spelling of 161560725 in words is "one hundred sixty-one million, five hundred sixty thousand, seven hundred twenty-five".