21232120111231 has 4 divisors (see below), whose sum is σ = 21549017426392. Its totient is φ = 20915222796072.

The previous prime is 21232120111187. The next prime is 21232120111291. The reversal of 21232120111231 is 13211102123212.

It is a happy number.

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 21232120111231 - 2³¹ = 21229972627583 is a prime.

It is a super-2 number, since 2×21232120111231² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21232120111291) 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, 158448657480 + ... + 158448657613.

It is an arithmetic number, because the mean of its divisors is an integer number (5387254356598).

Almost surely, 2^{21232120111231} is an apocalyptic number.

21232120111231 is a deficient number, since it is larger than the sum of its proper divisors (316897315161).

21232120111231 is an equidigital number, since it uses as much as digits as its factorization.

21232120111231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 316897315160.

The product of its (nonzero) digits is 288, while the sum is 22.

Adding to 21232120111231 its reverse (13211102123212), we get a palindrome (34443222234443).

The spelling of 21232120111231 in words is "twenty-one trillion, two hundred thirty-two billion, one hundred twenty million, one hundred eleven thousand, two hundred thirty-one".