21031102321 has 4 divisors (see below), whose sum is σ = 21079009600. Its totient is φ = 20983195044.

The previous prime is 21031102307. The next prime is 21031102349. The reversal of 21031102321 is 12320113012.

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 not a de Polignac number, because 21031102321 - 2²⁵ = 20997547889 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21031102295 and 21031102304.

It is not an unprimeable number, because it can be changed into a prime (21031102021) 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, 23952981 + ... + 23953858.

It is an arithmetic number, because the mean of its divisors is an integer number (5269752400).

Almost surely, 2^21031102321 is an apocalyptic number.

It is an amenable number.

21031102321 is a deficient number, since it is larger than the sum of its proper divisors (47907279).

21031102321 is an equidigital number, since it uses as much as digits as its factorization.

21031102321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47907278.

The product of its (nonzero) digits is 72, while the sum is 16.

Adding to 21031102321 its reverse (12320113012), we get a palindrome (33351215333).

The spelling of 21031102321 in words is "twenty-one billion, thirty-one million, one hundred two thousand, three hundred twenty-one".