21310032021 has 4 divisors (see below), whose sum is σ = 28413376032. Its totient is φ = 14206688012.

The previous prime is 21310031987. The next prime is 21310032041. The reversal of 21310032021 is 12023001312.

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 21310032021 - 2⁷ = 21310031893 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21310032041) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3551672001 + ... + 3551672006.

It is an arithmetic number, because the mean of its divisors is an integer number (7103344008).

Almost surely, 2^21310032021 is an apocalyptic number.

It is an amenable number.

21310032021 is a deficient number, since it is larger than the sum of its proper divisors (7103344011).

21310032021 is an equidigital number, since it uses as much as digits as its factorization.

21310032021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7103344010.

The product of its (nonzero) digits is 72, while the sum is 15.

Adding to 21310032021 its reverse (12023001312), we get a palindrome (33333033333).

The spelling of 21310032021 in words is "twenty-one billion, three hundred ten million, thirty-two thousand, twenty-one".