21992438823 has 4 divisors (see below), whose sum is σ = 29323251768. Its totient is φ = 14661625880.

The previous prime is 21992438821. The next prime is 21992438837. The reversal of 21992438823 is 32883429912.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21992438823 - 2¹ = 21992438821 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21992438821) 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, 3665406468 + ... + 3665406473.

It is an arithmetic number, because the mean of its divisors is an integer number (7330812942).

Almost surely, 2^21992438823 is an apocalyptic number.

21992438823 is a deficient number, since it is larger than the sum of its proper divisors (7330812945).

21992438823 is an equidigital number, since it uses as much as digits as its factorization.

21992438823 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7330812944.

The product of its digits is 1492992, while the sum is 51.

The spelling of 21992438823 in words is "twenty-one billion, nine hundred ninety-two million, four hundred thirty-eight thousand, eight hundred twenty-three".