21213233231 has 8 divisors (see below), whose sum is σ = 21309643728. Its totient is φ = 21117040000.

The previous prime is 21213233227. The next prime is 21213233317. The reversal of 21213233231 is 13233231212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21213233231 - 2² = 21213233227 is a prime.

It is a super-2 number, since 2×21213233231² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21213233197 and 21213233206.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21213233831) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 143021 + ... + 250761.

It is an arithmetic number, because the mean of its divisors is an integer number (2663705466).

Almost surely, 2^21213233231 is an apocalyptic number.

21213233231 is a deficient number, since it is larger than the sum of its proper divisors (96410497).

21213233231 is a wasteful number, since it uses less digits than its factorization.

21213233231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 108633.

The product of its digits is 1296, while the sum is 23.

Adding to 21213233231 its reverse (13233231212), we get a palindrome (34446464443).

The spelling of 21213233231 in words is "twenty-one billion, two hundred thirteen million, two hundred thirty-three thousand, two hundred thirty-one".