21179887775999 has 16 divisors (see below), whose sum is σ = 22133315888640. Its totient is φ = 20229193094880.

The previous prime is 21179887775957. The next prime is 21179887776011. The reversal of 21179887775999 is 99957778897112.

It is a de Polignac number, because none of the positive numbers 2^k-21179887775999 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 (21179887775909) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 47131232 + ... + 47578490.

It is an arithmetic number, because the mean of its divisors is an integer number (1383332243040).

Almost surely, 2^{21179887775999} is an apocalyptic number.

21179887775999 is a deficient number, since it is larger than the sum of its proper divisors (953428112641).

21179887775999 is a wasteful number, since it uses less digits than its factorization.

21179887775999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 450310.

The product of its digits is 10081895040, while the sum is 89.

The spelling of 21179887775999 in words is "twenty-one trillion, one hundred seventy-nine billion, eight hundred eighty-seven million, seven hundred seventy-five thousand, nine hundred ninety-nine".