172031561 has 8 divisors (see below), whose sum is σ = 185371200. Its totient is φ = 158707152.

The previous prime is 172031557. The next prime is 172031569. The reversal of 172031561 is 165130271.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 172031561 - 2² = 172031557 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 172031561.

It is not an unprimeable number, because it can be changed into a prime (172031569) 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 7 ways as a sum of consecutive naturals, for example, 32636 + ... + 37538.

It is an arithmetic number, because the mean of its divisors is an integer number (23171400).

Almost surely, 2^172031561 is an apocalyptic number.

It is an amenable number.

172031561 is a deficient number, since it is larger than the sum of its proper divisors (13339639).

172031561 is a wasteful number, since it uses less digits than its factorization.

172031561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7615.

The product of its (nonzero) digits is 1260, while the sum is 26.

The square root of 172031561 is about 13116.0802452562. The cubic root of 172031561 is about 556.1637900987.

The spelling of 172031561 in words is "one hundred seventy-two million, thirty-one thousand, five hundred sixty-one".