161517231 has 12 divisors (see below), whose sum is σ = 234307008. Its totient is φ = 107214624.

The previous prime is 161517229. The next prime is 161517241. The reversal of 161517231 is 132715161.

161517231 is a `hidden beast` number, since 1 + 615 + 17 + 2 + 31 = 666.

161517231 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 161517231 - 2¹ = 161517229 is a prime.

It is a super-2 number, since 2×161517231² = 52175631819814722, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 161517195 and 161517204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161517241) 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, 36415 + ... + 40608.

It is an arithmetic number, because the mean of its divisors is an integer number (19525584).

Almost surely, 2^161517231 is an apocalyptic number.

161517231 is a deficient number, since it is larger than the sum of its proper divisors (72789777).

161517231 is a wasteful number, since it uses less digits than its factorization.

161517231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 77262 (or 77259 counting only the distinct ones).

The product of its digits is 1260, while the sum is 27.

The square root of 161517231 is about 12708.9429536842. The cubic root of 161517231 is about 544.5941270136.

The spelling of 161517231 in words is "one hundred sixty-one million, five hundred seventeen thousand, two hundred thirty-one".