251021132505173 has 2 divisors, whose sum is σ = 251021132505174. Its totient is φ = 251021132505172.

The previous prime is 251021132505103. The next prime is 251021132505203. The reversal of 251021132505173 is 371505231120152.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 157941126256369 + 93080006248804 = 12567463^2 + 9647798^2 .

It is a cyclic number.

It is not a de Polignac number, because 251021132505173 - 2⁸ = 251021132504917 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (251021132505103) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 125510566252586 + 125510566252587.

It is an arithmetic number, because the mean of its divisors is an integer number (125510566252587).

Almost surely, 2^{251021132505173} is an apocalyptic number.

It is an amenable number.

251021132505173 is a deficient number, since it is larger than the sum of its proper divisors (1).

251021132505173 is an equidigital number, since it uses as much as digits as its factorization.

251021132505173 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 63000, while the sum is 38.

The spelling of 251021132505173 in words is "two hundred fifty-one trillion, twenty-one billion, one hundred thirty-two million, five hundred five thousand, one hundred seventy-three".