861872270645 has 16 divisors (see below), whose sum is σ = 1090635373440. Its totient is φ = 652035691584.

The previous prime is 861872270627. The next prime is 861872270647. The reversal of 861872270645 is 546072278168.

It is a cyclic number.

It is not a de Polignac number, because 861872270645 - 2²⁶ = 861805161781 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (861872270647) 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, 8091017 + ... + 8196846.

It is an arithmetic number, because the mean of its divisors is an integer number (68164710840).

Almost surely, 2^861872270645 is an apocalyptic number.

It is an amenable number.

861872270645 is a deficient number, since it is larger than the sum of its proper divisors (228763102795).

861872270645 is a wasteful number, since it uses less digits than its factorization.

861872270645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16288444.

The product of its (nonzero) digits is 9031680, while the sum is 56.

The spelling of 861872270645 in words is "eight hundred sixty-one billion, eight hundred seventy-two million, two hundred seventy thousand, six hundred forty-five".