256338621 has 64 divisors (see below), whose sum is σ = 477849600. Its totient is φ = 133032240.

The previous prime is 256338619. The next prime is 256338623. The reversal of 256338621 is 126833652.

It is a happy number.

256338621 is a `hidden beast` number, since 2 + 563 + 38 + 62 + 1 = 666.

It is an interprime number because it is at equal distance from previous prime (256338619) and next prime (256338623).

It is not a de Polignac number, because 256338621 - 2¹ = 256338619 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256338623) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 251050 + ... + 252068.

It is an arithmetic number, because the mean of its divisors is an integer number (7466400).

Almost surely, 2^256338621 is an apocalyptic number.

256338621 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

256338621 is a deficient number, since it is larger than the sum of its proper divisors (221510979).

256338621 is a wasteful number, since it uses less digits than its factorization.

256338621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1068 (or 1040 counting only the distinct ones).

The product of its digits is 51840, while the sum is 36.

The square root of 256338621 is about 16010.5784092893. The cubic root of 256338621 is about 635.2402595909.

The spelling of 256338621 in words is "two hundred fifty-six million, three hundred thirty-eight thousand, six hundred twenty-one".