257805313 has 4 divisors (see below), whose sum is σ = 259535700. Its totient is φ = 256074928.

The previous prime is 257805299. The next prime is 257805329. The reversal of 257805313 is 313508752.

257805313 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It can be written as a sum of positive squares in 2 ways, for example, as 135769104 + 122036209 = 11652^2 + 11047^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-257805313 is a prime.

It is a super-2 number, since 2×257805313² = 132927158822055938, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (257805013) 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, 864970 + ... + 865267.

It is an arithmetic number, because the mean of its divisors is an integer number (64883925).

Almost surely, 2^257805313 is an apocalyptic number.

It is an amenable number.

257805313 is a deficient number, since it is larger than the sum of its proper divisors (1730387).

257805313 is a wasteful number, since it uses less digits than its factorization.

257805313 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1730386.

The product of its (nonzero) digits is 25200, while the sum is 34.

The square root of 257805313 is about 16056.3169188952. The cubic root of 257805313 is about 636.4495070287.

The spelling of 257805313 in words is "two hundred fifty-seven million, eight hundred five thousand, three hundred thirteen".