21791899799 has 8 divisors (see below), whose sum is σ = 22196601648. Its totient is φ = 21388728960.

The previous prime is 21791899793. The next prime is 21791899819. The reversal of 21791899799 is 99799819712.

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

It is a cyclic number.

It is not a de Polignac number, because 21791899799 - 2⁸ = 21791899543 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 (21791899793) 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, 354002 + ... + 410975.

It is an arithmetic number, because the mean of its divisors is an integer number (2774575206).

Almost surely, 2^21791899799 is an apocalyptic number.

21791899799 is a deficient number, since it is larger than the sum of its proper divisors (404701849).

21791899799 is an equidigital number, since it uses as much as digits as its factorization.

21791899799 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 765505.

The product of its digits is 46294416, while the sum is 71.

The spelling of 21791899799 in words is "twenty-one billion, seven hundred ninety-one million, eight hundred ninety-nine thousand, seven hundred ninety-nine".