172661157 has 24 divisors (see below), whose sum is σ = 260933400. Its totient is φ = 109874688.

The previous prime is 172661141. The next prime is 172661179. The reversal of 172661157 is 751166271.

172661157 is a `hidden beast` number, since 17 + 26 + 611 + 5 + 7 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 159201 + 172501956 = 399^2 + 13134^2 .

It is not a de Polignac number, because 172661157 - 2⁴ = 172661141 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (172661107) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 19513 + ... + 26945.

It is an arithmetic number, because the mean of its divisors is an integer number (10872225).

Almost surely, 2^172661157 is an apocalyptic number.

It is an amenable number.

172661157 is a deficient number, since it is larger than the sum of its proper divisors (88272243).

172661157 is a wasteful number, since it uses less digits than its factorization.

172661157 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7557 (or 7554 counting only the distinct ones).

The product of its digits is 17640, while the sum is 36.

The square root of 172661157 is about 13140.0592464418. The cubic root of 172661157 is about 556.8414413301.

The spelling of 172661157 in words is "one hundred seventy-two million, six hundred sixty-one thousand, one hundred fifty-seven".