31132012321 has 4 divisors (see below), whose sum is σ = 31182799252. Its totient is φ = 31081225392.

The previous prime is 31132012309. The next prime is 31132012361. The reversal of 31132012321 is 12321023113.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12321023113 = 7 ⋅1760146159.

It can be written as a sum of positive squares in 2 ways, for example, as 10986184225 + 20145828096 = 104815^2 + 141936^2 .

It is a cyclic number.

It is not a de Polignac number, because 31132012321 - 2⁷ = 31132012193 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31132012361) 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, 25392546 + ... + 25393771.

It is an arithmetic number, because the mean of its divisors is an integer number (7795699813).

Almost surely, 2^31132012321 is an apocalyptic number.

It is an amenable number.

31132012321 is a deficient number, since it is larger than the sum of its proper divisors (50786931).

31132012321 is an equidigital number, since it uses as much as digits as its factorization.

31132012321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50786930.

The product of its (nonzero) digits is 216, while the sum is 19.

Adding to 31132012321 its reverse (12321023113), we get a palindrome (43453035434).

The spelling of 31132012321 in words is "thirty-one billion, one hundred thirty-two million, twelve thousand, three hundred twenty-one".