21917573983 has 4 divisors (see below), whose sum is σ = 22134579768. Its totient is φ = 21700568200.

The previous prime is 21917573981. The next prime is 21917574083. The reversal of 21917573983 is 38937571912.

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 21917573983 - 2¹ = 21917573981 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21917573981) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 108502741 + ... + 108502942.

It is an arithmetic number, because the mean of its divisors is an integer number (5533644942).

Almost surely, 2^21917573983 is an apocalyptic number.

21917573983 is a deficient number, since it is larger than the sum of its proper divisors (217005785).

21917573983 is a wasteful number, since it uses less digits than its factorization.

21917573983 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 217005784.

The product of its digits is 2857680, while the sum is 55.

The spelling of 21917573983 in words is "twenty-one billion, nine hundred seventeen million, five hundred seventy-three thousand, nine hundred eighty-three".