21939349718 has 32 divisors (see below), whose sum is σ = 38672992512. Its totient is φ = 9202788000.

The previous prime is 21939349703. The next prime is 21939349741. The reversal of 21939349718 is 81794393912.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1325393 + ... + 1341843.

It is an arithmetic number, because the mean of its divisors is an integer number (1208531016).

Almost surely, 2^21939349718 is an apocalyptic number.

21939349718 is a deficient number, since it is larger than the sum of its proper divisors (16733642794).

21939349718 is a wasteful number, since it uses less digits than its factorization.

21939349718 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21140.

The product of its digits is 2939328, while the sum is 56.

The spelling of 21939349718 in words is "twenty-one billion, nine hundred thirty-nine million, three hundred forty-nine thousand, seven hundred eighteen".