2556191 has 4 divisors (see below), whose sum is σ = 2788584. Its totient is φ = 2323800.

The previous prime is 2556187. The next prime is 2556193. The reversal of 2556191 is 1916552.

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 2556191 - 2² = 2556187 is a prime.

It is a super-2 number, since 2×2556191² = 13068224856962, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2556193) 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, 116180 + ... + 116201.

It is an arithmetic number, because the mean of its divisors is an integer number (697146).

2^2556191 is an apocalyptic number.

2556191 is a deficient number, since it is larger than the sum of its proper divisors (232393).

2556191 is a wasteful number, since it uses less digits than its factorization.

2556191 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 232392.

The product of its digits is 2700, while the sum is 29.

The square root of 2556191 is about 1598.8092444066. The cubic root of 2556191 is about 136.7301951986.

It can be divided in two parts, 25561 and 91, that added together give a palindrome (25652).

The spelling of 2556191 in words is "two million, five hundred fifty-six thousand, one hundred ninety-one".