8578722921 has 4 divisors (see below), whose sum is σ = 11438297232. Its totient is φ = 5719148612.

The previous prime is 8578722883. The next prime is 8578722973. The reversal of 8578722921 is 1292278758.

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 8578722921 - 2⁷ = 8578722793 is a prime.

It is not an unprimeable number, because it can be changed into a prime (8578722991) 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, 1429787151 + ... + 1429787156.

It is an arithmetic number, because the mean of its divisors is an integer number (2859574308).

Almost surely, 2^8578722921 is an apocalyptic number.

It is an amenable number.

8578722921 is a deficient number, since it is larger than the sum of its proper divisors (2859574311).

8578722921 is a wasteful number, since it uses less digits than its factorization.

8578722921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2859574310.

The product of its digits is 1128960, while the sum is 51.

The square root of 8578722921 is about 92621.3955897880. The cubic root of 8578722921 is about 2047.1085885046.

The spelling of 8578722921 in words is "eight billion, five hundred seventy-eight million, seven hundred twenty-two thousand, nine hundred twenty-one".