21579367793 has 4 divisors (see below), whose sum is σ = 21579959808. Its totient is φ = 21578775780.

The previous prime is 21579367787. The next prime is 21579367801. The reversal of 21579367793 is 39776397512.

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 21579367793 - 2⁶ = 21579367729 is a prime.

It is a super-2 number, since 2×21579367793² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21579367783) 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, 237473 + ... + 315518.

It is an arithmetic number, because the mean of its divisors is an integer number (5394989952).

Almost surely, 2^21579367793 is an apocalyptic number.

It is an amenable number.

21579367793 is a deficient number, since it is larger than the sum of its proper divisors (592015).

21579367793 is an equidigital number, since it uses as much as digits as its factorization.

21579367793 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 592014.

The product of its digits is 15002820, while the sum is 59.

The spelling of 21579367793 in words is "twenty-one billion, five hundred seventy-nine million, three hundred sixty-seven thousand, seven hundred ninety-three".