21640850799 has 4 divisors (see below), whose sum is σ = 28854467736. Its totient is φ = 14427233864.

The previous prime is 21640850773. The next prime is 21640850839. The reversal of 21640850799 is 99705804612.

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 21640850799 - 2²⁹ = 21103979887 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21640850899) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3606808464 + ... + 3606808469.

It is an arithmetic number, because the mean of its divisors is an integer number (7213616934).

Almost surely, 2^21640850799 is an apocalyptic number.

21640850799 is a deficient number, since it is larger than the sum of its proper divisors (7213616937).

21640850799 is an equidigital number, since it uses as much as digits as its factorization.

21640850799 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7213616936.

The product of its (nonzero) digits is 1088640, while the sum is 51.

The spelling of 21640850799 in words is "twenty-one billion, six hundred forty million, eight hundred fifty thousand, seven hundred ninety-nine".