31881863933 has 2 divisors, whose sum is σ = 31881863934. Its totient is φ = 31881863932.

The previous prime is 31881863921. The next prime is 31881863939. The reversal of 31881863933 is 33936818813.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 25154911609 + 6726952324 = 158603^2 + 82018^2 .

It is an emirp because it is prime and its reverse (33936818813) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31881863933 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31881863939) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15940931966 + 15940931967.

It is an arithmetic number, because the mean of its divisors is an integer number (15940931967).

Almost surely, 2^31881863933 is an apocalyptic number.

It is an amenable number.

31881863933 is a deficient number, since it is larger than the sum of its proper divisors (1).

31881863933 is an equidigital number, since it uses as much as digits as its factorization.

31881863933 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2239488, while the sum is 53.

The spelling of 31881863933 in words is "thirty-one billion, eight hundred eighty-one million, eight hundred sixty-three thousand, nine hundred thirty-three".