256620101 has 4 divisors (see below), whose sum is σ = 265469100. Its totient is φ = 247771104.

The previous prime is 256620073. The next prime is 256620163. The reversal of 256620101 is 101026652.

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 140541025 + 116079076 = 11855^2 + 10774^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-256620101 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 (256620601) 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, 4424456 + ... + 4424513.

It is an arithmetic number, because the mean of its divisors is an integer number (66367275).

Almost surely, 2^256620101 is an apocalyptic number.

It is an amenable number.

256620101 is a deficient number, since it is larger than the sum of its proper divisors (8848999).

256620101 is an equidigital number, since it uses as much as digits as its factorization.

256620101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8848998.

The product of its (nonzero) digits is 720, while the sum is 23.

The square root of 256620101 is about 16019.3664356616. The cubic root of 256620101 is about 635.4726891526.

Adding to 256620101 its reverse (101026652), we get a palindrome (357646753).

The spelling of 256620101 in words is "two hundred fifty-six million, six hundred twenty thousand, one hundred one".