172589075921 has 2 divisors, whose sum is σ = 172589075922. Its totient is φ = 172589075920.

The previous prime is 172589075899. The next prime is 172589075933. The reversal of 172589075921 is 129570985271.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 171591463696 + 997612225 = 414236^2 + 31585^2 .

It is a cyclic number.

It is not a de Polignac number, because 172589075921 - 2²² = 172584881617 is a prime.

It is not a weakly prime, because it can be changed into another prime (172589075221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 86294537960 + 86294537961.

It is an arithmetic number, because the mean of its divisors is an integer number (86294537961).

Almost surely, 2^172589075921 is an apocalyptic number.

It is an amenable number.

172589075921 is a deficient number, since it is larger than the sum of its proper divisors (1).

172589075921 is an equidigital number, since it uses as much as digits as its factorization.

172589075921 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3175200, while the sum is 56.

The spelling of 172589075921 in words is "one hundred seventy-two billion, five hundred eighty-nine million, seventy-five thousand, nine hundred twenty-one".