231550520150021 has 2 divisors, whose sum is σ = 231550520150022. Its totient is φ = 231550520150020.

The previous prime is 231550520150017. The next prime is 231550520150149. The reversal of 231550520150021 is 120051025055132.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 231472307637796 + 78212512225 = 15214214^2 + 279665^2 .

It is a cyclic number.

It is not a de Polignac number, because 231550520150021 - 2² = 231550520150017 is a prime.

It is a super-2 number, since 2×231550520150021² (a number of 30 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 231550520150021.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (231550520150011) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 115775260075010 + 115775260075011.

It is an arithmetic number, because the mean of its divisors is an integer number (115775260075011).

Almost surely, 2^{231550520150021} is an apocalyptic number.

It is an amenable number.

231550520150021 is a deficient number, since it is larger than the sum of its proper divisors (1).

231550520150021 is an equidigital number, since it uses as much as digits as its factorization.

231550520150021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 15000, while the sum is 32.

The spelling of 231550520150021 in words is "two hundred thirty-one trillion, five hundred fifty billion, five hundred twenty million, one hundred fifty thousand, twenty-one".