31113012121 has 4 divisors (see below), whose sum is σ = 31131722752. Its totient is φ = 31094301492.

The previous prime is 31113012109. The next prime is 31113012131. The reversal of 31113012121 is 12121031113.

It is a happy number.

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, and also an emirpimes, since its reverse is a distinct semiprime: 12121031113 = 47 ⋅257894279.

It is a cyclic number.

It is not a de Polignac number, because 31113012121 - 2⁵ = 31113012089 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 31113012095 and 31113012104.

It is not an unprimeable number, because it can be changed into a prime (31113012131) 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, 9352821 + ... + 9356146.

It is an arithmetic number, because the mean of its divisors is an integer number (7782930688).

Almost surely, 2^31113012121 is an apocalyptic number.

It is an amenable number.

31113012121 is a deficient number, since it is larger than the sum of its proper divisors (18710631).

31113012121 is a wasteful number, since it uses less digits than its factorization.

31113012121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18710630.

The product of its (nonzero) digits is 36, while the sum is 16.

Adding to 31113012121 its reverse (12121031113), we get a palindrome (43234043234).

The spelling of 31113012121 in words is "thirty-one billion, one hundred thirteen million, twelve thousand, one hundred twenty-one".