2556409251 has 16 divisors (see below), whose sum is σ = 3727266048. Its totient is φ = 1545650400.

The previous prime is 2556409249. The next prime is 2556409253. The reversal of 2556409251 is 1529046552.

It is an interprime number because it is at equal distance from previous prime (2556409249) and next prime (2556409253).

It is not a de Polignac number, because 2556409251 - 2¹ = 2556409249 is a prime.

It is not an unprimeable number, because it can be changed into a prime (2556409253) 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, 78111 + ... + 105896.

It is an arithmetic number, because the mean of its divisors is an integer number (232954128).

Almost surely, 2^2556409251 is an apocalyptic number.

2556409251 is a deficient number, since it is larger than the sum of its proper divisors (1170856797).

2556409251 is a wasteful number, since it uses less digits than its factorization.

2556409251 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 184442.

The product of its (nonzero) digits is 108000, while the sum is 39.

The square root of 2556409251 is about 50560.9459068954. The cubic root of 2556409251 is about 1367.3408649004.

The spelling of 2556409251 in words is "two billion, five hundred fifty-six million, four hundred nine thousand, two hundred fifty-one".