2556381421 has 4 divisors (see below), whose sum is σ = 2788779744. Its totient is φ = 2323983100.

The previous prime is 2556381413. The next prime is 2556381463. The reversal of 2556381421 is 1241836552.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 2556381421 - 2³ = 2556381413 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 15.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2556381221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 116199145 + ... + 116199166.

It is an arithmetic number, because the mean of its divisors is an integer number (697194936).

Almost surely, 2^2556381421 is an apocalyptic number.

It is an amenable number.

2556381421 is a deficient number, since it is larger than the sum of its proper divisors (232398323).

2556381421 is a wasteful number, since it uses less digits than its factorization.

2556381421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 232398322.

The product of its digits is 57600, while the sum is 37.

The square root of 2556381421 is about 50560.6706937319. The cubic root of 2556381421 is about 1367.3359030926.

The spelling of 2556381421 in words is "two billion, five hundred fifty-six million, three hundred eighty-one thousand, four hundred twenty-one".