21650652021 has 4 divisors (see below), whose sum is σ = 28867536032. Its totient is φ = 14433768012.

The previous prime is 21650652011. The next prime is 21650652029. The reversal of 21650652021 is 12025605612.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 21650652021 - 2³³ = 13060717429 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21650652021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21650652029) 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, 3608442001 + ... + 3608442006.

It is an arithmetic number, because the mean of its divisors is an integer number (7216884008).

Almost surely, 2^21650652021 is an apocalyptic number.

It is an amenable number.

21650652021 is a deficient number, since it is larger than the sum of its proper divisors (7216884011).

21650652021 is an equidigital number, since it uses as much as digits as its factorization.

21650652021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7216884010.

The product of its (nonzero) digits is 7200, while the sum is 30.

The spelling of 21650652021 in words is "twenty-one billion, six hundred fifty million, six hundred fifty-two thousand, twenty-one".