21303132121 has 4 divisors (see below), whose sum is σ = 21316886500. Its totient is φ = 21289377744.

The previous prime is 21303132107. The next prime is 21303132131. The reversal of 21303132121 is 12123130312.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 4961089225 + 16342042896 = 70435^2 + 127836^2 .

It is a cyclic number.

It is not a de Polignac number, because 21303132121 - 2⁹ = 21303131609 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21303132131) 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, 6874866 + ... + 6877963.

It is an arithmetic number, because the mean of its divisors is an integer number (5329221625).

Almost surely, 2^21303132121 is an apocalyptic number.

It is an amenable number.

21303132121 is a deficient number, since it is larger than the sum of its proper divisors (13754379).

21303132121 is a wasteful number, since it uses less digits than its factorization.

21303132121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13754378.

The product of its (nonzero) digits is 216, while the sum is 19.

Adding to 21303132121 its reverse (12123130312), we get a palindrome (33426262433).

The spelling of 21303132121 in words is "twenty-one billion, three hundred three million, one hundred thirty-two thousand, one hundred twenty-one".