256635431 has 8 divisors (see below), whose sum is σ = 277826304. Its totient is φ = 235651680.

The previous prime is 256635409. The next prime is 256635439. The reversal of 256635431 is 134536652.

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-256635431 is a prime.

It is a super-2 number, since 2×256635431² = 131723488889111522, 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 = 256635391 and 256635400.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256635439) 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 7 ways as a sum of consecutive naturals, for example, 49196 + ... + 54161.

It is an arithmetic number, because the mean of its divisors is an integer number (34728288).

Almost surely, 2^256635431 is an apocalyptic number.

256635431 is a deficient number, since it is larger than the sum of its proper divisors (21190873).

256635431 is a wasteful number, since it uses less digits than its factorization.

256635431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 103561.

The product of its digits is 64800, while the sum is 35.

The square root of 256635431 is about 16019.8449118585. The cubic root of 256635431 is about 635.4853428799.

The spelling of 256635431 in words is "two hundred fifty-six million, six hundred thirty-five thousand, four hundred thirty-one".