21791923873 has 8 divisors (see below), whose sum is σ = 22973827968. Its totient is φ = 20629555584.

The previous prime is 21791923849. The next prime is 21791923877. The reversal of 21791923873 is 37832919712.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21791923873 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21791923873.

It is not an unprimeable number, because it can be changed into a prime (21791923877) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4881661 + ... + 4886122.

It is an arithmetic number, because the mean of its divisors is an integer number (2871728496).

Almost surely, 2^21791923873 is an apocalyptic number.

21791923873 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

It is an amenable number.

21791923873 is a deficient number, since it is larger than the sum of its proper divisors (1181904095).

21791923873 is an equidigital number, since it uses as much as digits as its factorization.

21791923873 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9767903.

The product of its digits is 1143072, while the sum is 52.

The spelling of 21791923873 in words is "twenty-one billion, seven hundred ninety-one million, nine hundred twenty-three thousand, eight hundred seventy-three".