256308641 has 8 divisors (see below), whose sum is σ = 269495400. Its totient is φ = 243411840.

The previous prime is 256308631. The next prime is 256308649. The reversal of 256308641 is 146803652.

It can be written as a sum of positive squares in 4 ways, for example, as 10916416 + 245392225 = 3304^2 + 15665^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-256308641 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (256308649) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 70676 + ... + 74213.

It is an arithmetic number, because the mean of its divisors is an integer number (33686925).

Almost surely, 2^256308641 is an apocalyptic number.

It is an amenable number.

256308641 is a deficient number, since it is larger than the sum of its proper divisors (13186759).

256308641 is a wasteful number, since it uses less digits than its factorization.

256308641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 144979.

The product of its (nonzero) digits is 34560, while the sum is 35.

The square root of 256308641 is about 16009.6421259190. The cubic root of 256308641 is about 635.2154938528.

The spelling of 256308641 in words is "two hundred fifty-six million, three hundred eight thousand, six hundred forty-one".