21210110231 has 4 divisors (see below), whose sum is σ = 22457763792. Its totient is φ = 19962456672.

The previous prime is 21210110183. The next prime is 21210110263. The reversal of 21210110231 is 13201101212.

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

It is a cyclic number.

It is not a de Polignac number, because 21210110231 - 2¹⁸ = 21209848087 is a prime.

It is a super-2 number, since 2×21210110231² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21210110291) 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, 623826755 + ... + 623826788.

It is an arithmetic number, because the mean of its divisors is an integer number (5614440948).

Almost surely, 2^21210110231 is an apocalyptic number.

21210110231 is a deficient number, since it is larger than the sum of its proper divisors (1247653561).

21210110231 is a wasteful number, since it uses less digits than its factorization.

21210110231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1247653560.

The product of its (nonzero) digits is 24, while the sum is 14.

Adding to 21210110231 its reverse (13201101212), we get a palindrome (34411211443).

The spelling of 21210110231 in words is "twenty-one billion, two hundred ten million, one hundred ten thousand, two hundred thirty-one".