256689776 has 40 divisors (see below), whose sum is σ = 572567520. Its totient is φ = 109200384.

The previous prime is 256689767. The next prime is 256689781. The reversal of 256689776 is 677986652.

256689776 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×256689776² = 131779282205860352, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (56).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6980 + ... + 23708.

It is an arithmetic number, because the mean of its divisors is an integer number (14314188).

Almost surely, 2^256689776 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 256689776, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (286283760).

256689776 is an abundant number, since it is smaller than the sum of its proper divisors (315877744).

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

256689776 is a wasteful number, since it uses less digits than its factorization.

256689776 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16881 (or 16875 counting only the distinct ones).

The product of its digits is 7620480, while the sum is 56.

The square root of 256689776 is about 16021.5409995418. The cubic root of 256689776 is about 635.5301964079.

The spelling of 256689776 in words is "two hundred fifty-six million, six hundred eighty-nine thousand, seven hundred seventy-six".