161525985 has 16 divisors (see below), whose sum is σ = 258992640. Its totient is φ = 85963520.

The previous prime is 161525951. The next prime is 161525989. The reversal of 161525985 is 589525161.

It is a happy number.

It is not a de Polignac number, because 161525985 - 2⁸ = 161525729 is a prime.

It is not an unprimeable number, because it can be changed into a prime (161525989) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4056 + ... + 18425.

It is an arithmetic number, because the mean of its divisors is an integer number (16187040).

Almost surely, 2^161525985 is an apocalyptic number.

161525985 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

161525985 is a deficient number, since it is larger than the sum of its proper divisors (97466655).

161525985 is a wasteful number, since it uses less digits than its factorization.

161525985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22968.

The product of its digits is 108000, while the sum is 42.

The square root of 161525985 is about 12709.2873521689. The cubic root of 161525985 is about 544.6039655735.

The spelling of 161525985 in words is "one hundred sixty-one million, five hundred twenty-five thousand, nine hundred eighty-five".