21993166699 has 32 divisors (see below), whose sum is σ = 26335051776. Its totient is φ = 17974323360.

The previous prime is 21993166693. The next prime is 21993166709. The reversal of 21993166699 is 99666139912.

It is not a de Polignac number, because 21993166699 - 2¹¹ = 21993164651 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21993166693) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 6095554 + ... + 6099160.

It is an arithmetic number, because the mean of its divisors is an integer number (822970368).

Almost surely, 2^21993166699 is an apocalyptic number.

21993166699 is a deficient number, since it is larger than the sum of its proper divisors (4341885077).

21993166699 is a wasteful number, since it uses less digits than its factorization.

21993166699 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4135.

The product of its digits is 8503056, while the sum is 61.

The spelling of 21993166699 in words is "twenty-one billion, nine hundred ninety-three million, one hundred sixty-six thousand, six hundred ninety-nine".