2556375221 has 6 divisors (see below), whose sum is σ = 2715596130. Its totient is φ = 2405999936.

The previous prime is 2556375209. The next prime is 2556375233. The reversal of 2556375221 is 1225736552.

2556375221 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (2556375209) and next prime (2556375233).

It can be written as a sum of positive squares in 3 ways, for example, as 921790321 + 1634584900 = 30361^2 + 40430^2 .

It is a de Polignac number, because none of the positive numbers 2^k-2556375221 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 (2556375281) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4422506 + ... + 4423083.

It is an arithmetic number, because the mean of its divisors is an integer number (452599355).

Almost surely, 2^2556375221 is an apocalyptic number.

It is an amenable number.

2556375221 is a deficient number, since it is larger than the sum of its proper divisors (159220909).

2556375221 is an equidigital number, since it uses as much as digits as its factorization.

2556375221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8845623 (or 8845606 counting only the distinct ones).

The product of its digits is 126000, while the sum is 38.

The square root of 2556375221 is about 50560.6093812169. The cubic root of 2556375221 is about 1367.3347976903.

The spelling of 2556375221 in words is "two billion, five hundred fifty-six million, three hundred seventy-five thousand, two hundred twenty-one".