2551591491 has 16 divisors (see below), whose sum is σ = 3664467840. Its totient is φ = 1574052480.

The previous prime is 2551591451. The next prime is 2551591519. The reversal of 2551591491 is 1941951552.

It is not a de Polignac number, because 2551591491 - 2⁷ = 2551591363 is a prime.

It is not an unprimeable number, because it can be changed into a prime (2551591451) 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, 518070 + ... + 522971.

It is an arithmetic number, because the mean of its divisors is an integer number (229029240).

Almost surely, 2^2551591491 is an apocalyptic number.

2551591491 is a deficient number, since it is larger than the sum of its proper divisors (1112876349).

2551591491 is a wasteful number, since it uses less digits than its factorization.

2551591491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1041106.

The product of its digits is 81000, while the sum is 42.

The square root of 2551591491 is about 50513.2803428960. The cubic root of 2551591491 is about 1366.4813699273.

The spelling of 2551591491 in words is "two billion, five hundred fifty-one million, five hundred ninety-one thousand, four hundred ninety-one".