256640111 has 32 divisors (see below), whose sum is σ = 331161600. Its totient is φ = 193415040.

The previous prime is 256640107. The next prime is 256640113. The reversal of 256640111 is 111046652.

256640111 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 256640111 - 2² = 256640107 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256640113) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 207866 + ... + 209096.

It is an arithmetic number, because the mean of its divisors is an integer number (10348800).

Almost surely, 2^256640111 is an apocalyptic number.

256640111 is a deficient number, since it is larger than the sum of its proper divisors (74521489).

256640111 is a wasteful number, since it uses less digits than its factorization.

256640111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1359.

The product of its (nonzero) digits is 1440, while the sum is 26.

The square root of 256640111 is about 16019.9909800224. The cubic root of 256640111 is about 635.4892057569.

Adding to 256640111 its reverse (111046652), we get a palindrome (367686763).

The spelling of 256640111 in words is "two hundred fifty-six million, six hundred forty thousand, one hundred eleven".