21693392873 has 4 divisors (see below), whose sum is σ = 21777803220. Its totient is φ = 21608982528.

The previous prime is 21693392837. The next prime is 21693392921. The reversal of 21693392873 is 37829339612.

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

It can be written as a sum of positive squares in 2 ways, for example, as 21114124249 + 579268624 = 145307^2 + 24068^2 .

It is a cyclic number.

It is not a de Polignac number, because 21693392873 - 2²² = 21689198569 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21693392813) 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, 42204788 + ... + 42205301.

It is an arithmetic number, because the mean of its divisors is an integer number (5444450805).

Almost surely, 2^21693392873 is an apocalyptic number.

It is an amenable number.

21693392873 is a deficient number, since it is larger than the sum of its proper divisors (84410347).

21693392873 is an equidigital number, since it uses as much as digits as its factorization.

21693392873 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 84410346.

The product of its digits is 2939328, while the sum is 53.

The spelling of 21693392873 in words is "twenty-one billion, six hundred ninety-three million, three hundred ninety-two thousand, eight hundred seventy-three".