21917768439 has 8 divisors (see below), whose sum is σ = 33398504320. Its totient is φ = 12524439096.

The previous prime is 21917768371. The next prime is 21917768443. The reversal of 21917768439 is 93486771912.

It is a happy number.

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

It is not a de Polignac number, because 21917768439 - 2⁷ = 21917768311 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 (21917768239) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 521851609 + ... + 521851650.

It is an arithmetic number, because the mean of its divisors is an integer number (4174813040).

Almost surely, 2^21917768439 is an apocalyptic number.

21917768439 is a deficient number, since it is larger than the sum of its proper divisors (11480735881).

21917768439 is a wasteful number, since it uses less digits than its factorization.

21917768439 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1043703269.

The product of its digits is 4572288, while the sum is 57.

The spelling of 21917768439 in words is "twenty-one billion, nine hundred seventeen million, seven hundred sixty-eight thousand, four hundred thirty-nine".