172725621 has 4 divisors (see below), whose sum is σ = 230300832. Its totient is φ = 115150412.

The previous prime is 172725613. The next prime is 172725629. The reversal of 172725621 is 126527271.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is an interprime number because it is at equal distance from previous prime (172725613) and next prime (172725629).

It is a cyclic number.

It is not a de Polignac number, because 172725621 - 2³ = 172725613 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (172725629) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 28787601 + ... + 28787606.

It is an arithmetic number, because the mean of its divisors is an integer number (57575208).

Almost surely, 2^172725621 is an apocalyptic number.

It is an amenable number.

172725621 is a deficient number, since it is larger than the sum of its proper divisors (57575211).

172725621 is an equidigital number, since it uses as much as digits as its factorization.

172725621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57575210.

The product of its digits is 11760, while the sum is 33.

The square root of 172725621 is about 13142.5119745047. The cubic root of 172725621 is about 556.9107326535.

The spelling of 172725621 in words is "one hundred seventy-two million, seven hundred twenty-five thousand, six hundred twenty-one".