251696064689 has 4 divisors (see below), whose sum is σ = 251852496420. Its totient is φ = 251539632960.

The previous prime is 251696064673. The next prime is 251696064701. The reversal of 251696064689 is 986460696152.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 193277174689 + 58418890000 = 439633^2 + 241700^2 .

It is a cyclic number.

It is not a de Polignac number, because 251696064689 - 2⁴ = 251696064673 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (251696064619) 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, 78213452 + ... + 78216669.

It is an arithmetic number, because the mean of its divisors is an integer number (62963124105).

Almost surely, 2^251696064689 is an apocalyptic number.

It is an amenable number.

251696064689 is a deficient number, since it is larger than the sum of its proper divisors (156431731).

251696064689 is a wasteful number, since it uses less digits than its factorization.

251696064689 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 156431730.

The product of its (nonzero) digits is 33592320, while the sum is 62.

The spelling of 251696064689 in words is "two hundred fifty-one billion, six hundred ninety-six million, sixty-four thousand, six hundred eighty-nine".