21202320031 has 4 divisors (see below), whose sum is σ = 21274683192. Its totient is φ = 21129956872.

The previous prime is 21202320011. The next prime is 21202320067. The reversal of 21202320031 is 13002320212.

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 21202320031 - 2⁷ = 21202319903 is a prime.

It is a super-2 number, since 2×21202320031² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21202319987 and 21202320014.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21202320011) 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, 36181141 + ... + 36181726.

It is an arithmetic number, because the mean of its divisors is an integer number (5318670798).

Almost surely, 2^21202320031 is an apocalyptic number.

21202320031 is a deficient number, since it is larger than the sum of its proper divisors (72363161).

21202320031 is an equidigital number, since it uses as much as digits as its factorization.

21202320031 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 72363160.

The product of its (nonzero) digits is 144, while the sum is 16.

Adding to 21202320031 its reverse (13002320212), we get a palindrome (34204640243).

The spelling of 21202320031 in words is "twenty-one billion, two hundred two million, three hundred twenty thousand, thirty-one".