172605621 has 16 divisors (see below), whose sum is σ = 236692800. Its totient is φ = 111838848.

The previous prime is 172605619. The next prime is 172605637. The reversal of 172605621 is 126506271.

It is not a de Polignac number, because 172605621 - 2¹ = 172605619 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (172605611) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10275 + ... + 21231.

It is an arithmetic number, because the mean of its divisors is an integer number (14793300).

Almost surely, 2^172605621 is an apocalyptic number.

It is an amenable number.

172605621 is a deficient number, since it is larger than the sum of its proper divisors (64087179).

172605621 is a wasteful number, since it uses less digits than its factorization.

172605621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11108.

The product of its (nonzero) digits is 5040, while the sum is 30.

The square root of 172605621 is about 13137.9458440047. The cubic root of 172605621 is about 556.7817327404.

The spelling of 172605621 in words is "one hundred seventy-two million, six hundred five thousand, six hundred twenty-one".