21217699199 has 4 divisors (see below), whose sum is σ = 21436438464. Its totient is φ = 20998959936.

The previous prime is 21217699193. The next prime is 21217699207. The reversal of 21217699199 is 99199671212.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21217699199 - 2²⁸ = 20949263743 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 (21217699193) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 109369487 + ... + 109369680.

It is an arithmetic number, because the mean of its divisors is an integer number (5359109616).

Almost surely, 2^21217699199 is an apocalyptic number.

21217699199 is a deficient number, since it is larger than the sum of its proper divisors (218739265).

21217699199 is an equidigital number, since it uses as much as digits as its factorization.

21217699199 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 218739264.

The product of its digits is 1102248, while the sum is 56.

The spelling of 21217699199 in words is "twenty-one billion, two hundred seventeen million, six hundred ninety-nine thousand, one hundred ninety-nine".