256588421 has 4 divisors (see below), whose sum is σ = 256648992. Its totient is φ = 256527852.

The previous prime is 256588403. The next prime is 256588469. The reversal of 256588421 is 124885652.

It is a happy number.

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 256588421 - 2¹⁸ = 256326277 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 (256588471) 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, 23411 + ... + 32576.

It is an arithmetic number, because the mean of its divisors is an integer number (64162248).

Almost surely, 2^256588421 is an apocalyptic number.

It is an amenable number.

256588421 is a deficient number, since it is larger than the sum of its proper divisors (60571).

256588421 is an equidigital number, since it uses as much as digits as its factorization.

256588421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 60570.

The product of its digits is 153600, while the sum is 41.

The square root of 256588421 is about 16018.3776019920. The cubic root of 256588421 is about 635.4465381701.

The spelling of 256588421 in words is "two hundred fifty-six million, five hundred eighty-eight thousand, four hundred twenty-one".