251015221505231 has 2 divisors, whose sum is σ = 251015221505232. Its totient is φ = 251015221505230.

The previous prime is 251015221505077. The next prime is 251015221505239. The reversal of 251015221505231 is 132505122510152.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 251015221505231 - 2¹⁰ = 251015221504207 is a prime.

It is a super-2 number, since 2×251015221505231² (a number of 30 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a junction number, because it is equal to n+sod(n) for n = 251015221505191 and 251015221505200.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (251015221505239) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 125507610752615 + 125507610752616.

It is an arithmetic number, because the mean of its divisors is an integer number (125507610752616).

Almost surely, 2^{251015221505231} is an apocalyptic number.

251015221505231 is a deficient number, since it is larger than the sum of its proper divisors (1).

251015221505231 is an equidigital number, since it uses as much as digits as its factorization.

251015221505231 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 30000, while the sum is 35.

The spelling of 251015221505231 in words is "two hundred fifty-one trillion, fifteen billion, two hundred twenty-one million, five hundred five thousand, two hundred thirty-one".