2556380873981 has 6 divisors (see below), whose sum is σ = 2809906250046. Its totient is φ = 2323982612600.

The previous prime is 2556380873941. The next prime is 2556380873989. The reversal of 2556380873981 is 1893780836552.

It can be written as a sum of positive squares in only one way, i.e., 1676077193956 + 880303680025 = 1294634^2 + 938245^2 .

It is not a de Polignac number, because 2556380873981 - 2²² = 2556376679677 is a prime.

It is a super-2 number, since 2×2556380873981² (a number of 26 digits) 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 (2556380873989) 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, 10563557210 + ... + 10563557451.

It is an arithmetic number, because the mean of its divisors is an integer number (468317708341).

Almost surely, 2^{2556380873981} is an apocalyptic number.

It is an amenable number.

2556380873981 is a deficient number, since it is larger than the sum of its proper divisors (253525376065).

2556380873981 is a wasteful number, since it uses less digits than its factorization.

2556380873981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21127114683 (or 21127114672 counting only the distinct ones).

The product of its (nonzero) digits is 87091200, while the sum is 65.

The spelling of 2556380873981 in words is "two trillion, five hundred fifty-six billion, three hundred eighty million, eight hundred seventy-three thousand, nine hundred eighty-one".