251132918381 has 2 divisors, whose sum is σ = 251132918382. Its totient is φ = 251132918380.

The previous prime is 251132918339. The next prime is 251132918419. The reversal of 251132918381 is 183819231152.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 172668505156 + 78464413225 = 415534^2 + 280115^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-251132918381 is a prime.

It is a super-2 number, since 2×251132918381² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (251132918321) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 125566459190 + 125566459191.

It is an arithmetic number, because the mean of its divisors is an integer number (125566459191).

Almost surely, 2^251132918381 is an apocalyptic number.

It is an amenable number.

251132918381 is a deficient number, since it is larger than the sum of its proper divisors (1).

251132918381 is an equidigital number, since it uses as much as digits as its factorization.

251132918381 is an evil number, because the sum of its binary digits is even.

The product of its digits is 103680, while the sum is 44.

The spelling of 251132918381 in words is "two hundred fifty-one billion, one hundred thirty-two million, nine hundred eighteen thousand, three hundred eighty-one".