161566525 has 12 divisors (see below), whose sum is σ = 204124212. Its totient is φ = 126813440.

The previous prime is 161566507. The next prime is 161566543. The reversal of 161566525 is 525665161.

It is an interprime number because it is at equal distance from previous prime (161566507) and next prime (161566543).

It can be written as a sum of positive squares in 6 ways, for example, as 8450649 + 153115876 = 2907^2 + 12374^2 .

It is not a de Polignac number, because 161566525 - 2⁷ = 161566397 is a prime.

It is a super-2 number, since 2×161566525² = 52207484001151250, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

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, 59644 + ... + 62293.

It is an arithmetic number, because the mean of its divisors is an integer number (17010351).

Almost surely, 2^161566525 is an apocalyptic number.

It is an amenable number.

161566525 is a deficient number, since it is larger than the sum of its proper divisors (42557687).

161566525 is a wasteful number, since it uses less digits than its factorization.

161566525 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 122000 (or 121995 counting only the distinct ones).

The product of its digits is 54000, while the sum is 37.

The square root of 161566525 is about 12710.8821487732. The cubic root of 161566525 is about 544.6495235641.

The spelling of 161566525 in words is "one hundred sixty-one million, five hundred sixty-six thousand, five hundred twenty-five".