251591007601 has 4 divisors (see below), whose sum is σ = 264832639600. Its totient is φ = 238349375604.

The previous prime is 251591007583. The next prime is 251591007641. The reversal of 251591007601 is 106700195152.

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 251591007601 - 2⁹ = 251591007089 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (251591007641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6620815971 + ... + 6620816008.

It is an arithmetic number, because the mean of its divisors is an integer number (66208159900).

Almost surely, 2^251591007601 is an apocalyptic number.

It is an amenable number.

251591007601 is a deficient number, since it is larger than the sum of its proper divisors (13241631999).

251591007601 is a wasteful number, since it uses less digits than its factorization.

251591007601 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13241631998.

The product of its (nonzero) digits is 18900, while the sum is 37.

The spelling of 251591007601 in words is "two hundred fifty-one billion, five hundred ninety-one million, seven thousand, six hundred one".