21200233220021 has 4 divisors (see below), whose sum is σ = 21204838967232. Its totient is φ = 21195627472812.

The previous prime is 21200233220009. The next prime is 21200233220053. The reversal of 21200233220021 is 12002233200212.

It is a happy number.

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 a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21200233220021 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21200233219975 and 21200233220002.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21200233220081) 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, 2302866701 + ... + 2302875906.

It is an arithmetic number, because the mean of its divisors is an integer number (5301209741808).

Almost surely, 2^{21200233220021} is an apocalyptic number.

It is an amenable number.

21200233220021 is a deficient number, since it is larger than the sum of its proper divisors (4605747211).

21200233220021 is an equidigital number, since it uses as much as digits as its factorization.

21200233220021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4605747210.

The product of its (nonzero) digits is 576, while the sum is 20.

Adding to 21200233220021 its reverse (12002233200212), we get a palindrome (33202466420233).

The spelling of 21200233220021 in words is "twenty-one trillion, two hundred billion, two hundred thirty-three million, two hundred twenty thousand, twenty-one".