31899493 has 2 divisors, whose sum is σ = 31899494. Its totient is φ = 31899492.

The previous prime is 31899487. The next prime is 31899521. The reversal of 31899493 is 39499813.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18809569 + 13089924 = 4337^2 + 3618^2 .

It is an emirp because it is prime and its reverse (39499813) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 31899493 - 2⁹ = 31898981 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31899433) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15949746 + 15949747.

It is an arithmetic number, because the mean of its divisors is an integer number (15949747).

Almost surely, 2^31899493 is an apocalyptic number.

It is an amenable number.

31899493 is a deficient number, since it is larger than the sum of its proper divisors (1).

31899493 is an equidigital number, since it uses as much as digits as its factorization.

31899493 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 209952, while the sum is 46.

The square root of 31899493 is about 5647.9636153219. The cubic root of 31899493 is about 317.1474765503.

The spelling of 31899493 in words is "thirty-one million, eight hundred ninety-nine thousand, four hundred ninety-three".