21113312231 has 32 divisors (see below), whose sum is σ = 25648939008. Its totient is φ = 17142935040.

The previous prime is 21113312179. The next prime is 21113312281. The reversal of 21113312231 is 13221331112.

It is a happy number.

It is not a de Polignac number, because 21113312231 - 2¹⁰ = 21113311207 is a prime.

It is a super-2 number, since 2×21113312231² (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 (21113312281) 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, 526901 + ... + 565553.

It is an arithmetic number, because the mean of its divisors is an integer number (801529344).

Almost surely, 2^21113312231 is an apocalyptic number.

21113312231 is a deficient number, since it is larger than the sum of its proper divisors (4535626777).

21113312231 is a wasteful number, since it uses less digits than its factorization.

21113312231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38831.

The product of its digits is 216, while the sum is 20.

Adding to 21113312231 its reverse (13221331112), we get a palindrome (34334643343).

The spelling of 21113312231 in words is "twenty-one billion, one hundred thirteen million, three hundred twelve thousand, two hundred thirty-one".