21232321231 has 4 divisors (see below), whose sum is σ = 23162532264. Its totient is φ = 19302110200.

The previous prime is 21232321199. The next prime is 21232321273. The reversal of 21232321231 is 13212323212.

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 21232321231 - 2⁵ = 21232321199 is a prime.

It is a super-2 number, since 2×21232321231² (a number of 21 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21232321291) 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, 965105500 + ... + 965105521.

It is an arithmetic number, because the mean of its divisors is an integer number (5790633066).

Almost surely, 2^21232321231 is an apocalyptic number.

21232321231 is a deficient number, since it is larger than the sum of its proper divisors (1930211033).

21232321231 is a wasteful number, since it uses less digits than its factorization.

21232321231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1930211032.

The product of its digits is 864, while the sum is 22.

Adding to 21232321231 its reverse (13212323212), we get a palindrome (34444644443).

The spelling of 21232321231 in words is "twenty-one billion, two hundred thirty-two million, three hundred twenty-one thousand, two hundred thirty-one".