21948597799 has 4 divisors (see below), whose sum is σ = 21949234720. Its totient is φ = 21947960880.

The previous prime is 21948597793. The next prime is 21948597823. The reversal of 21948597799 is 99779584912.

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 21948597799 - 2²³ = 21940209191 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 (21948597793) 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, 263622 + ... + 336739.

It is an arithmetic number, because the mean of its divisors is an integer number (5487308680).

Almost surely, 2^21948597799 is an apocalyptic number.

21948597799 is a deficient number, since it is larger than the sum of its proper divisors (636921).

21948597799 is an equidigital number, since it uses as much as digits as its factorization.

21948597799 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 636920.

The product of its digits is 102876480, while the sum is 70.

The spelling of 21948597799 in words is "twenty-one billion, nine hundred forty-eight million, five hundred ninety-seven thousand, seven hundred ninety-nine".