256667653 has 4 divisors (see below), whose sum is σ = 280001088. Its totient is φ = 233334220.

The previous prime is 256667647. The next prime is 256667701. The reversal of 256667653 is 356766652.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-256667653 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256667633) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11666701 + ... + 11666722.

It is an arithmetic number, because the mean of its divisors is an integer number (70000272).

Almost surely, 2^256667653 is an apocalyptic number.

It is an amenable number.

256667653 is a deficient number, since it is larger than the sum of its proper divisors (23333435).

256667653 is a wasteful number, since it uses less digits than its factorization.

256667653 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23333434.

The product of its digits is 1360800, while the sum is 46.

The square root of 256667653 is about 16020.8505704285. The cubic root of 256667653 is about 635.5119380019.

The spelling of 256667653 in words is "two hundred fifty-six million, six hundred sixty-seven thousand, six hundred fifty-three".