21899709215 has 4 divisors (see below), whose sum is σ = 26279651064. Its totient is φ = 17519767368.

The previous prime is 21899709203. The next prime is 21899709229. The reversal of 21899709215 is 51290799812.

It is a happy number.

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 21899709215 - 2⁴ = 21899709199 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2189970917 + ... + 2189970926.

It is an arithmetic number, because the mean of its divisors is an integer number (6569912766).

Almost surely, 2^21899709215 is an apocalyptic number.

21899709215 is a deficient number, since it is larger than the sum of its proper divisors (4379941849).

21899709215 is an equidigital number, since it uses as much as digits as its factorization.

21899709215 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4379941848.

The product of its (nonzero) digits is 816480, while the sum is 53.

The spelling of 21899709215 in words is "twenty-one billion, eight hundred ninety-nine million, seven hundred nine thousand, two hundred fifteen".