256764019 has 4 divisors (see below), whose sum is σ = 267927696. Its totient is φ = 245600344.

The previous prime is 256763993. The next prime is 256764023. The reversal of 256764019 is 910467652.

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 256764019 - 2⁵ = 256763987 is a prime.

It is a super-2 number, since 2×256764019² = 131855522906064722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (256764029) 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, 5581804 + ... + 5581849.

It is an arithmetic number, because the mean of its divisors is an integer number (66981924).

Almost surely, 2^256764019 is an apocalyptic number.

256764019 is a deficient number, since it is larger than the sum of its proper divisors (11163677).

256764019 is a wasteful number, since it uses less digits than its factorization.

256764019 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11163676.

The product of its (nonzero) digits is 90720, while the sum is 40.

The square root of 256764019 is about 16023.8578064085. The cubic root of 256764019 is about 635.5914624763.

The spelling of 256764019 in words is "two hundred fifty-six million, seven hundred sixty-four thousand, nineteen".