256621061366013 has 16 divisors (see below), whose sum is σ = 343670224524480. Its totient is φ = 170326309430016.

The previous prime is 256621061366003. The next prime is 256621061366023. The reversal of 256621061366013 is 310663160126652.

It is an interprime number because it is at equal distance from previous prime (256621061366003) and next prime (256621061366023).

It is not a de Polignac number, because 256621061366013 - 2¹³ = 256621061357821 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256621061366003) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 188523381 + ... + 189879717.

It is an arithmetic number, because the mean of its divisors is an integer number (21479389032780).

Almost surely, 2^{256621061366013} is an apocalyptic number.

It is an amenable number.

256621061366013 is a deficient number, since it is larger than the sum of its proper divisors (87049163158467).

256621061366013 is a wasteful number, since it uses less digits than its factorization.

256621061366013 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1634396.

The product of its (nonzero) digits is 1399680, while the sum is 48.

The spelling of 256621061366013 in words is "two hundred fifty-six trillion, six hundred twenty-one billion, sixty-one million, three hundred sixty-six thousand, thirteen".