31181365121 has 4 divisors (see below), whose sum is σ = 32537076672. Its totient is φ = 29825653572.

The previous prime is 31181365109. The next prime is 31181365151. The reversal of 31181365121 is 12156318113.

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: 12156318113 = 137 ⋅88732249.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31181365121 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31181365151) 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, 677855741 + ... + 677855786.

It is an arithmetic number, because the mean of its divisors is an integer number (8134269168).

Almost surely, 2^31181365121 is an apocalyptic number.

It is an amenable number.

31181365121 is a deficient number, since it is larger than the sum of its proper divisors (1355711551).

31181365121 is a wasteful number, since it uses less digits than its factorization.

31181365121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1355711550.

The product of its digits is 4320, while the sum is 32.

The spelling of 31181365121 in words is "thirty-one billion, one hundred eighty-one million, three hundred sixty-five thousand, one hundred twenty-one".