31431893 has 2 divisors, whose sum is σ = 31431894. Its totient is φ = 31431892.

The previous prime is 31431859. The next prime is 31431899. The reversal of 31431893 is 39813413.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18992164 + 12439729 = 4358^2 + 3527^2 .

It is an emirp because it is prime and its reverse (39813413) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 31431893 - 2⁸ = 31431637 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31431899) 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, 15715946 + 15715947.

It is an arithmetic number, because the mean of its divisors is an integer number (15715947).

Almost surely, 2^31431893 is an apocalyptic number.

It is an amenable number.

31431893 is a deficient number, since it is larger than the sum of its proper divisors (1).

31431893 is an equidigital number, since it uses as much as digits as its factorization.

31431893 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7776, while the sum is 32.

The square root of 31431893 is about 5606.4153431582. The cubic root of 31431893 is about 315.5902027841.

The spelling of 31431893 in words is "thirty-one million, four hundred thirty-one thousand, eight hundred ninety-three".