251530561426613 has 4 divisors (see below), whose sum is σ = 287463498773280. Its totient is φ = 215597624079948.

The previous prime is 251530561426601. The next prime is 251530561426631. The reversal of 251530561426613 is 316624165035152.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 251530561426613 - 2⁶ = 251530561426549 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (251530561426213) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 17966468673323 + ... + 17966468673336.

It is an arithmetic number, because the mean of its divisors is an integer number (71865874693320).

Almost surely, 2^{251530561426613} is an apocalyptic number.

It is an amenable number.

251530561426613 is a deficient number, since it is larger than the sum of its proper divisors (35932937346667).

251530561426613 is an equidigital number, since it uses as much as digits as its factorization.

251530561426613 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35932937346666.

The product of its (nonzero) digits is 3888000, while the sum is 50.

The spelling of 251530561426613 in words is "two hundred fifty-one trillion, five hundred thirty billion, five hundred sixty-one million, four hundred twenty-six thousand, six hundred thirteen".