31218544139 has 2 divisors, whose sum is σ = 31218544140. Its totient is φ = 31218544138.

The previous prime is 31218544103. The next prime is 31218544171. The reversal of 31218544139 is 93144581213.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31218544139 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 31218544096 and 31218544105.

It is not a weakly prime, because it can be changed into another prime (31218544199) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15609272069 + 15609272070.

It is an arithmetic number, because the mean of its divisors is an integer number (15609272070).

Almost surely, 2^31218544139 is an apocalyptic number.

31218544139 is a deficient number, since it is larger than the sum of its proper divisors (1).

31218544139 is an equidigital number, since it uses as much as digits as its factorization.

31218544139 is an evil number, because the sum of its binary digits is even.

The product of its digits is 103680, while the sum is 41.

The spelling of 31218544139 in words is "thirty-one billion, two hundred eighteen million, five hundred forty-four thousand, one hundred thirty-nine".