22131232221 has 16 divisors (see below), whose sum is σ = 33898523264. Its totient is φ = 12580890624.

The previous prime is 22131232219. The next prime is 22131232223. The reversal of 22131232221 is 12223213122.

It is an interprime number because it is at equal distance from previous prime (22131232219) and next prime (22131232223).

It is not a de Polignac number, because 22131232221 - 2¹ = 22131232219 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (22131232223) 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, 2726176 + ... + 2734281.

It is an arithmetic number, because the mean of its divisors is an integer number (2118657704).

Almost surely, 2^22131232221 is an apocalyptic number.

22131232221 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

22131232221 is a deficient number, since it is larger than the sum of its proper divisors (11767291043).

22131232221 is a wasteful number, since it uses less digits than its factorization.

22131232221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5460660.

The product of its digits is 576, while the sum is 21.

Adding to 22131232221 its reverse (12223213122), we get a palindrome (34354445343).

The spelling of 22131232221 in words is "twenty-two billion, one hundred thirty-one million, two hundred thirty-two thousand, two hundred twenty-one".