31123012013 has 4 divisors (see below), whose sum is σ = 31128494208. Its totient is φ = 31117529820.

The previous prime is 31123011991. The next prime is 31123012031. The reversal of 31123012013 is 31021032113.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 31123012013 - 2⁶ = 31123011949 is a prime.

It is a super-2 number, since 2×31123012013² (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 = 31123011982 and 31123012000.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31123012043) 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, 2732573 + ... + 2743938.

It is an arithmetic number, because the mean of its divisors is an integer number (7782123552).

Almost surely, 2^31123012013 is an apocalyptic number.

It is an amenable number.

31123012013 is a deficient number, since it is larger than the sum of its proper divisors (5482195).

31123012013 is an equidigital number, since it uses as much as digits as its factorization.

31123012013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5482194.

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

Adding to 31123012013 its reverse (31021032113), we get a palindrome (62144044126).

The spelling of 31123012013 in words is "thirty-one billion, one hundred twenty-three million, twelve thousand, thirteen".