251132561216 has 14 divisors (see below), whose sum is σ = 498341176290. Its totient is φ = 125566280576.

The previous prime is 251132561167. The next prime is 251132561221. The reversal of 251132561216 is 612165231152.

It can be written as a sum of positive squares in only one way, i.e., 239998090816 + 11134470400 = 489896^2 + 105520^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1961973071 + ... + 1961973198.

Almost surely, 2^251132561216 is an apocalyptic number.

It is an amenable number.

251132561216 is a deficient number, since it is larger than the sum of its proper divisors (247208615074).

251132561216 is an equidigital number, since it uses as much as digits as its factorization.

251132561216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3923946281 (or 3923946271 counting only the distinct ones).

The product of its digits is 21600, while the sum is 35.

Adding to 251132561216 its reverse (612165231152), we get a palindrome (863297792368).

The spelling of 251132561216 in words is "two hundred fifty-one billion, one hundred thirty-two million, five hundred sixty-one thousand, two hundred sixteen".