31329989 has 2 divisors, whose sum is σ = 31329990. Its totient is φ = 31329988.

The previous prime is 31329983. The next prime is 31330007. The reversal of 31329989 is 98992313.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 30713764 + 616225 = 5542^2 + 785^2 .

It is a cyclic number.

It is not a de Polignac number, because 31329989 - 2⁴ = 31329973 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31329983) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15664994 + 15664995.

It is an arithmetic number, because the mean of its divisors is an integer number (15664995).

Almost surely, 2^31329989 is an apocalyptic number.

It is an amenable number.

31329989 is a deficient number, since it is larger than the sum of its proper divisors (1).

31329989 is an equidigital number, since it uses as much as digits as its factorization.

31329989 is an evil number, because the sum of its binary digits is even.

The product of its digits is 104976, while the sum is 44.

The square root of 31329989 is about 5597.3198050496. The cubic root of 31329989 is about 315.2487797003.

The spelling of 31329989 in words is "thirty-one million, three hundred twenty-nine thousand, nine hundred eighty-nine".