31899534181 has 2 divisors, whose sum is σ = 31899534182. Its totient is φ = 31899534180.

The previous prime is 31899534151. The next prime is 31899534203. The reversal of 31899534181 is 18143599813.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 30114049156 + 1785485025 = 173534^2 + 42255^2 .

It is an emirp because it is prime and its reverse (18143599813) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31899534181 is a prime.

It is a super-2 number, since 2×31899534181² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31899534101) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15949767090 + 15949767091.

It is an arithmetic number, because the mean of its divisors is an integer number (15949767091).

Almost surely, 2^31899534181 is an apocalyptic number.

It is an amenable number.

31899534181 is a deficient number, since it is larger than the sum of its proper divisors (1).

31899534181 is an equidigital number, since it uses as much as digits as its factorization.

31899534181 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 933120, while the sum is 52.

The spelling of 31899534181 in words is "thirty-one billion, eight hundred ninety-nine million, five hundred thirty-four thousand, one hundred eighty-one".