312131120111221 has 4 divisors (see below), whose sum is σ = 312131605866444. Its totient is φ = 312130634356000.

The previous prime is 312131120111141. The next prime is 312131120111267. The reversal of 312131120111221 is 122111021131213.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 301588202027025 + 10542918084196 = 17366295^2 + 3246986^2 .

It is a cyclic number.

It is not a de Polignac number, because 312131120111221 - 2³³ = 312122530176629 is a prime.

It is a super-2 number, since 2×312131120111221² (a number of 30 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 312131120111192 and 312131120111201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (312131120114221) 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, 241912480 + ... + 243199321.

It is an arithmetic number, because the mean of its divisors is an integer number (78032901466611).

Almost surely, 2^{312131120111221} is an apocalyptic number.

It is an amenable number.

312131120111221 is a deficient number, since it is larger than the sum of its proper divisors (485755223).

312131120111221 is an equidigital number, since it uses as much as digits as its factorization.

312131120111221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 485755222.

The product of its (nonzero) digits is 144, while the sum is 22.

Adding to 312131120111221 its reverse (122111021131213), we get a palindrome (434242141242434).

The spelling of 312131120111221 in words is "three hundred twelve trillion, one hundred thirty-one billion, one hundred twenty million, one hundred eleven thousand, two hundred twenty-one".