251550980661 has 16 divisors (see below), whose sum is σ = 344605874624. Its totient is φ = 163102045824.

The previous prime is 251550980647. The next prime is 251550980711. The reversal of 251550980661 is 166089055152.

It is a de Polignac number, because none of the positive numbers 2^k-251550980661 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 251550980661.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (251550980621) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 183691 + ... + 732696.

It is an arithmetic number, because the mean of its divisors is an integer number (21537867164).

Almost surely, 2^251550980661 is an apocalyptic number.

It is an amenable number.

251550980661 is a deficient number, since it is larger than the sum of its proper divisors (93054893963).

251550980661 is a wasteful number, since it uses less digits than its factorization.

251550980661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 918900.

The product of its (nonzero) digits is 648000, while the sum is 48.

The spelling of 251550980661 in words is "two hundred fifty-one billion, five hundred fifty million, nine hundred eighty thousand, six hundred sixty-one".