31218518797 has 4 divisors (see below), whose sum is σ = 31220259136. Its totient is φ = 31216778460.

The previous prime is 31218518753. The next prime is 31218518857. The reversal of 31218518797 is 79781581213.

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: 79781581213 = 17 ⋅4693034189.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31218518797 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31218518297) 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, 842979 + ... + 879232.

It is an arithmetic number, because the mean of its divisors is an integer number (7805064784).

Almost surely, 2^31218518797 is an apocalyptic number.

It is an amenable number.

31218518797 is a deficient number, since it is larger than the sum of its proper divisors (1740339).

31218518797 is a wasteful number, since it uses less digits than its factorization.

31218518797 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1740338.

The product of its digits is 846720, while the sum is 52.

The spelling of 31218518797 in words is "thirty-one billion, two hundred eighteen million, five hundred eighteen thousand, seven hundred ninety-seven".