21310230021 has 16 divisors (see below), whose sum is σ = 28713573504. Its totient is φ = 14056925184.

The previous prime is 21310229989. The next prime is 21310230023. The reversal of 21310230021 is 12003201312.

It is not a de Polignac number, because 21310230021 - 2⁵ = 21310229989 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21310230023) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1842960 + ... + 1854486.

It is an arithmetic number, because the mean of its divisors is an integer number (1794598344).

Almost surely, 2^21310230021 is an apocalyptic number.

It is an amenable number.

21310230021 is a deficient number, since it is larger than the sum of its proper divisors (7403343483).

21310230021 is a wasteful number, since it uses less digits than its factorization.

21310230021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17980.

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

Adding to 21310230021 its reverse (12003201312), we get a palindrome (33313431333).

The spelling of 21310230021 in words is "twenty-one billion, three hundred ten million, two hundred thirty thousand, twenty-one".