31373989 has 2 divisors, whose sum is σ = 31373990. Its totient is φ = 31373988.

The previous prime is 31373987. The next prime is 31374011. The reversal of 31373989 is 98937313.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20205025 + 11168964 = 4495^2 + 3342^2 .

It is a cyclic number.

It is not a de Polignac number, because 31373989 - 2¹ = 31373987 is a prime.

Together with 31373987, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31373983) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15686994 + 15686995.

It is an arithmetic number, because the mean of its divisors is an integer number (15686995).

Almost surely, 2^31373989 is an apocalyptic number.

It is an amenable number.

31373989 is a deficient number, since it is larger than the sum of its proper divisors (1).

31373989 is an equidigital number, since it uses as much as digits as its factorization.

31373989 is an evil number, because the sum of its binary digits is even.

The product of its digits is 122472, while the sum is 43.

The square root of 31373989 is about 5601.2488785984. The cubic root of 31373989 is about 315.3962896775.

The spelling of 31373989 in words is "thirty-one million, three hundred seventy-three thousand, nine hundred eighty-nine".