251521132450513 has 2 divisors, whose sum is σ = 251521132450514. Its totient is φ = 251521132450512.

The previous prime is 251521132450501. The next prime is 251521132450543. The reversal of 251521132450513 is 315054231125152.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 176680241420544 + 74840891029969 = 13292112^2 + 8651063^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-251521132450513 is a prime.

It is not a weakly prime, because it can be changed into another prime (251521132450543) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 125760566225256 + 125760566225257.

It is an arithmetic number, because the mean of its divisors is an integer number (125760566225257).

Almost surely, 2^{251521132450513} is an apocalyptic number.

It is an amenable number.

251521132450513 is a deficient number, since it is larger than the sum of its proper divisors (1).

251521132450513 is an equidigital number, since it uses as much as digits as its factorization.

251521132450513 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 180000, while the sum is 40.

Adding to 251521132450513 its reverse (315054231125152), we get a palindrome (566575363575665).

The spelling of 251521132450513 in words is "two hundred fifty-one trillion, five hundred twenty-one billion, one hundred thirty-two million, four hundred fifty thousand, five hundred thirteen".