256612686 has 96 divisors (see below), whose sum is σ = 596048544. Its totient is φ = 73497600.

The previous prime is 256612669. The next prime is 256612709. The reversal of 256612686 is 686216652.

It is a super-2 number, since 2×256612686² = 131700141232269192, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1101226 + ... + 1101458.

It is an arithmetic number, because the mean of its divisors is an integer number (6208839).

Almost surely, 2^256612686 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 256612686, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (298024272).

256612686 is an abundant number, since it is smaller than the sum of its proper divisors (339435858).

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

256612686 is a wasteful number, since it uses less digits than its factorization.

256612686 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 338 (or 327 counting only the distinct ones).

The product of its digits is 207360, while the sum is 42.

The square root of 256612686 is about 16019.1349953735. The cubic root of 256612686 is about 635.4665684637.

The spelling of 256612686 in words is "two hundred fifty-six million, six hundred twelve thousand, six hundred eighty-six".