256640102 has 4 divisors (see below), whose sum is σ = 384960156. Its totient is φ = 128320050.

The previous prime is 256640093. The next prime is 256640107. The reversal of 256640102 is 201046652.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256640107) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64160024 + ... + 64160027.

It is an arithmetic number, because the mean of its divisors is an integer number (96240039).

Almost surely, 2^256640102 is an apocalyptic number.

256640102 is a deficient number, since it is larger than the sum of its proper divisors (128320054).

256640102 is a wasteful number, since it uses less digits than its factorization.

256640102 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 128320053.

The product of its (nonzero) digits is 2880, while the sum is 26.

The square root of 256640102 is about 16019.9906991234. The cubic root of 256640102 is about 635.4891983283.

Adding to 256640102 its reverse (201046652), we get a palindrome (457686754).

The spelling of 256640102 in words is "two hundred fifty-six million, six hundred forty thousand, one hundred two".