21398933986 has 16 divisors (see below), whose sum is σ = 32591844864. Its totient is φ = 10535469984.

The previous prime is 21398933981. The next prime is 21398933987. The reversal of 21398933986 is 68933989312.

It is not an unprimeable number, because it can be changed into a prime (21398933981) 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, 32110 + ... + 209353.

It is an arithmetic number, because the mean of its divisors is an integer number (2036990304).

Almost surely, 2^21398933986 is an apocalyptic number.

21398933986 is a deficient number, since it is larger than the sum of its proper divisors (11192910878).

21398933986 is a wasteful number, since it uses less digits than its factorization.

21398933986 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 242145.

The product of its digits is 15116544, while the sum is 61.

The spelling of 21398933986 in words is "twenty-one billion, three hundred ninety-eight million, nine hundred thirty-three thousand, nine hundred eighty-six".