256620431 has 4 divisors (see below), whose sum is σ = 262588392. Its totient is φ = 250652472.

The previous prime is 256620421. The next prime is 256620439. The reversal of 256620431 is 134026652.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 256620431 - 2⁶ = 256620367 is a prime.

It is a super-2 number, since 2×256620431² = 131708091213251522, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 256620394 and 256620403.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256620439) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2983916 + ... + 2984001.

It is an arithmetic number, because the mean of its divisors is an integer number (65647098).

Almost surely, 2^256620431 is an apocalyptic number.

256620431 is a deficient number, since it is larger than the sum of its proper divisors (5967961).

256620431 is an equidigital number, since it uses as much as digits as its factorization.

256620431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5967960.

The product of its (nonzero) digits is 8640, while the sum is 29.

The square root of 256620431 is about 16019.3767356911. The cubic root of 256620431 is about 635.4729615473.

The spelling of 256620431 in words is "two hundred fifty-six million, six hundred twenty thousand, four hundred thirty-one".