30999989 has 2 divisors, whose sum is σ = 30999990. Its totient is φ = 30999988.

The previous prime is 30999979. The next prime is 31000003. The reversal of 30999989 is 98999903.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 30713764 + 286225 = 5542^2 + 535^2 .

It is an emirp because it is prime and its reverse (98999903) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 30999989 - 2⁸ = 30999733 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (30999979) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15499994 + 15499995.

It is an arithmetic number, because the mean of its divisors is an integer number (15499995).

Almost surely, 2^30999989 is an apocalyptic number.

It is an amenable number.

30999989 is a deficient number, since it is larger than the sum of its proper divisors (1).

30999989 is an equidigital number, since it uses as much as digits as its factorization.

30999989 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1417176, while the sum is 56.

The square root of 30999989 is about 5567.7633750008. The cubic root of 30999989 is about 314.1380280830.

The spelling of 30999989 in words is "thirty million, nine hundred ninety-nine thousand, nine hundred eighty-nine".