31131120331 has 4 divisors (see below), whose sum is σ = 31134222792. Its totient is φ = 31128017872.

The previous prime is 31131120311. The next prime is 31131120367. The reversal of 31131120331 is 13302113113.

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 31131120331 - 2⁷ = 31131120203 is a prime.

It is a super-2 number, since 2×31131120331² (a number of 22 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 = 31131120299 and 31131120308.

It is not an unprimeable number, because it can be changed into a prime (31131120311) 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, 1536130 + ... + 1556263.

It is an arithmetic number, because the mean of its divisors is an integer number (7783555698).

Almost surely, 2^31131120331 is an apocalyptic number.

31131120331 is a deficient number, since it is larger than the sum of its proper divisors (3102461).

31131120331 is a wasteful number, since it uses less digits than its factorization.

31131120331 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3102460.

The product of its (nonzero) digits is 162, while the sum is 19.

Adding to 31131120331 its reverse (13302113113), we get a palindrome (44433233444).

The spelling of 31131120331 in words is "thirty-one billion, one hundred thirty-one million, one hundred twenty thousand, three hundred thirty-one".