256864564501 has 4 divisors (see below), whose sum is σ = 261711065772. Its totient is φ = 252018063232.

The previous prime is 256864564441. The next prime is 256864564513. The reversal of 256864564501 is 105465468652.

256864564501 = 358374² + 358375².

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

It can be written as a sum of positive squares in 2 ways, for example, as 128431923876 + 128432640625 = 358374^2 + 358375^2 .

It is a cyclic number.

It is not a de Polignac number, because 256864564501 - 2⁷ = 256864564373 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 (256864594501) 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, 2423250556 + ... + 2423250661.

It is an arithmetic number, because the mean of its divisors is an integer number (65427766443).

Almost surely, 2^256864564501 is an apocalyptic number.

256864564501 is the 358375-th centered square number.

It is an amenable number.

256864564501 is a deficient number, since it is larger than the sum of its proper divisors (4846501271).

256864564501 is an equidigital number, since it uses as much as digits as its factorization.

256864564501 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4846501270.

The product of its (nonzero) digits is 6912000, while the sum is 52.

The spelling of 256864564501 in words is "two hundred fifty-six billion, eight hundred sixty-four million, five hundred sixty-four thousand, five hundred one".