21302432121 has 4 divisors (see below), whose sum is σ = 28403242832. Its totient is φ = 14201621412.

The previous prime is 21302432119. The next prime is 21302432143. The reversal of 21302432121 is 12123420312.

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 21302432121 - 2¹ = 21302432119 is a prime.

It is a super-2 number, since 2×21302432121² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21302432111) 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, 3550405351 + ... + 3550405356.

It is an arithmetic number, because the mean of its divisors is an integer number (7100810708).

Almost surely, 2^21302432121 is an apocalyptic number.

It is an amenable number.

21302432121 is a deficient number, since it is larger than the sum of its proper divisors (7100810711).

21302432121 is an equidigital number, since it uses as much as digits as its factorization.

21302432121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7100810710.

The product of its (nonzero) digits is 576, while the sum is 21.

Adding to 21302432121 its reverse (12123420312), we get a palindrome (33425852433).

The spelling of 21302432121 in words is "twenty-one billion, three hundred two million, four hundred thirty-two thousand, one hundred twenty-one".