863872564721 has 4 divisors (see below), whose sum is σ = 901432241472. Its totient is φ = 826312887972.

The previous prime is 863872564717. The next prime is 863872564727. The reversal of 863872564721 is 127465278368.

863872564721 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 not a de Polignac number, because 863872564721 - 2² = 863872564717 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (863872564727) 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, 18779838341 + ... + 18779838386.

It is an arithmetic number, because the mean of its divisors is an integer number (225358060368).

Almost surely, 2^863872564721 is an apocalyptic number.

It is an amenable number.

863872564721 is a deficient number, since it is larger than the sum of its proper divisors (37559676751).

863872564721 is a wasteful number, since it uses less digits than its factorization.

863872564721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37559676750.

The product of its digits is 27095040, while the sum is 59.

The spelling of 863872564721 in words is "eight hundred sixty-three billion, eight hundred seventy-two million, five hundred sixty-four thousand, seven hundred twenty-one".