256670660729 has 4 divisors (see below), whose sum is σ = 293337897984. Its totient is φ = 220003423476.

The previous prime is 256670660713. The next prime is 256670660791. The reversal of 256670660729 is 927066076652.

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 256670660729 - 2⁴ = 256670660713 is a prime.

It is a super-2 number, since 2×256670660729² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (256670666729) 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, 18333618617 + ... + 18333618630.

It is an arithmetic number, because the mean of its divisors is an integer number (73334474496).

Almost surely, 2^256670660729 is an apocalyptic number.

It is an amenable number.

256670660729 is a deficient number, since it is larger than the sum of its proper divisors (36667237255).

256670660729 is an equidigital number, since it uses as much as digits as its factorization.

256670660729 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36667237254.

The product of its (nonzero) digits is 11430720, while the sum is 56.

The spelling of 256670660729 in words is "two hundred fifty-six billion, six hundred seventy million, six hundred sixty thousand, seven hundred twenty-nine".