31531438849 has 2 divisors, whose sum is σ = 31531438850. Its totient is φ = 31531438848.

The previous prime is 31531438843. The next prime is 31531438867. The reversal of 31531438849 is 94883413513.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 30348078849 + 1183360000 = 174207^2 + 34400^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31531438849 is a prime.

It is not a weakly prime, because it can be changed into another prime (31531438843) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15765719424 + 15765719425.

It is an arithmetic number, because the mean of its divisors is an integer number (15765719425).

Almost surely, 2^31531438849 is an apocalyptic number.

It is an amenable number.

31531438849 is a deficient number, since it is larger than the sum of its proper divisors (1).

31531438849 is an equidigital number, since it uses as much as digits as its factorization.

31531438849 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1244160, while the sum is 49.

The spelling of 31531438849 in words is "thirty-one billion, five hundred thirty-one million, four hundred thirty-eight thousand, eight hundred forty-nine".