251121140551 has 4 divisors (see below), whose sum is σ = 251172072504. Its totient is φ = 251070208600.

The previous prime is 251121140533. The next prime is 251121140591. The reversal of 251121140551 is 155041121152.

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

It is a cyclic number.

It is not a de Polignac number, because 251121140551 - 2⁵ = 251121140519 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 (251121140591) 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, 25458580 + ... + 25468441.

It is an arithmetic number, because the mean of its divisors is an integer number (62793018126).

Almost surely, 2^251121140551 is an apocalyptic number.

251121140551 is a deficient number, since it is larger than the sum of its proper divisors (50931953).

251121140551 is an equidigital number, since it uses as much as digits as its factorization.

251121140551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50931952.

The product of its (nonzero) digits is 2000, while the sum is 28.

The spelling of 251121140551 in words is "two hundred fifty-one billion, one hundred twenty-one million, one hundred forty thousand, five hundred fifty-one".