251262513217 has 2 divisors, whose sum is σ = 251262513218. Its totient is φ = 251262513216.

The previous prime is 251262513211. The next prime is 251262513233. The reversal of 251262513217 is 712315262152.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 127741193281 + 123521319936 = 357409^2 + 351456^2 .

It is a cyclic number.

It is not a de Polignac number, because 251262513217 - 2¹¹ = 251262511169 is a prime.

It is not a weakly prime, because it can be changed into another prime (251262513211) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 125631256608 + 125631256609.

It is an arithmetic number, because the mean of its divisors is an integer number (125631256609).

Almost surely, 2^251262513217 is an apocalyptic number.

It is an amenable number.

251262513217 is a deficient number, since it is larger than the sum of its proper divisors (1).

251262513217 is an equidigital number, since it uses as much as digits as its factorization.

251262513217 is an evil number, because the sum of its binary digits is even.

The product of its digits is 50400, while the sum is 37.

Adding to 251262513217 its reverse (712315262152), we get a palindrome (963577775369).

The spelling of 251262513217 in words is "two hundred fifty-one billion, two hundred sixty-two million, five hundred thirteen thousand, two hundred seventeen".