21572812799 has 4 divisors (see below), whose sum is σ = 22031808864. Its totient is φ = 21113816736.

The previous prime is 21572812787. The next prime is 21572812801. The reversal of 21572812799 is 99721827512.

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 21572812799 - 2²⁰ = 21571764223 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21572812799.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21572812739) 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, 229497962 + ... + 229498055.

It is an arithmetic number, because the mean of its divisors is an integer number (5507952216).

Almost surely, 2^21572812799 is an apocalyptic number.

21572812799 is a deficient number, since it is larger than the sum of its proper divisors (458996065).

21572812799 is an equidigital number, since it uses as much as digits as its factorization.

21572812799 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 458996064.

The product of its digits is 1270080, while the sum is 53.

The spelling of 21572812799 in words is "twenty-one billion, five hundred seventy-two million, eight hundred twelve thousand, seven hundred ninety-nine".