256690 has 32 divisors (see below), whose sum is σ = 558720. Its totient is φ = 82944.

The previous prime is 256687. The next prime is 256699. The reversal of 256690 is 96652.

It is a super-2 number, since 2×256690² = 131779512200, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256699) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1234 + ... + 1426.

It is an arithmetic number, because the mean of its divisors is an integer number (17460).

2²⁵⁶⁶⁹⁰ is an apocalyptic number.

256690 is an abundant number, since it is smaller than the sum of its proper divisors (302030).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

256690 is a wasteful number, since it uses less digits than its factorization.

256690 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 226.

The product of its (nonzero) digits is 3240, while the sum is 28.

The square root of 256690 is about 506.6458329050. The cubic root of 256690 is about 63.5530381273.

It can be divided in two parts, 256 and 690, that added together give a triangular number (946 = T₄₃).

The spelling of 256690 in words is "two hundred fifty-six thousand, six hundred ninety".