31131210023 has 4 divisors (see below), whose sum is σ = 31145820888. Its totient is φ = 31116599160.

The previous prime is 31131210017. The next prime is 31131210049. The reversal of 31131210023 is 32001213113.

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 31131210023 - 2¹² = 31131205927 is a prime.

It is a super-2 number, since 2×31131210023² (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 = 31131209983 and 31131210010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31131210083) 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, 7302236 + ... + 7306497.

It is an arithmetic number, because the mean of its divisors is an integer number (7786455222).

Almost surely, 2^31131210023 is an apocalyptic number.

31131210023 is a deficient number, since it is larger than the sum of its proper divisors (14610865).

31131210023 is a wasteful number, since it uses less digits than its factorization.

31131210023 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14610864.

The product of its (nonzero) digits is 108, while the sum is 17.

Adding to 31131210023 its reverse (32001213113), we get a palindrome (63132423136).

The spelling of 31131210023 in words is "thirty-one billion, one hundred thirty-one million, two hundred ten thousand, twenty-three".