21223213231 has 32 divisors (see below), whose sum is σ = 24182737920. Its totient is φ = 18449088000.

The previous prime is 21223213189. The next prime is 21223213241. The reversal of 21223213231 is 13231232212.

It is a cyclic number.

It is not a de Polignac number, because 21223213231 - 2¹³ = 21223205039 is a prime.

It is a super-2 number, since 2×21223213231² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21223213241) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 28563846 + ... + 28564588.

It is an arithmetic number, because the mean of its divisors is an integer number (755710560).

Almost surely, 2^21223213231 is an apocalyptic number.

21223213231 is a deficient number, since it is larger than the sum of its proper divisors (2959524689).

21223213231 is a wasteful number, since it uses less digits than its factorization.

21223213231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1527.

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

Adding to 21223213231 its reverse (13231232212), we get a palindrome (34454445443).

The spelling of 21223213231 in words is "twenty-one billion, two hundred twenty-three million, two hundred thirteen thousand, two hundred thirty-one".