256942686 has 128 divisors (see below), whose sum is σ = 696729600. Its totient is φ = 61004160.

The previous prime is 256942649. The next prime is 256942703. The reversal of 256942686 is 686249652.

It is a happy number.

256942686 is digitally balanced in base 2 and base 3, because in such bases it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1074955 + ... + 1075193.

It is an arithmetic number, because the mean of its divisors is an integer number (5443200).

Almost surely, 2^256942686 is an apocalyptic number.

256942686 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 256942686, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (348364800).

256942686 is an abundant number, since it is smaller than the sum of its proper divisors (439786914).

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

256942686 is a wasteful number, since it uses less digits than its factorization.

256942686 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 454.

The product of its digits is 1244160, while the sum is 48.

The square root of 256942686 is about 16029.4318676614. The cubic root of 256942686 is about 635.7388518843.

The spelling of 256942686 in words is "two hundred fifty-six million, nine hundred forty-two thousand, six hundred eighty-six".