30971989 has 2 divisors, whose sum is σ = 30971990. Its totient is φ = 30971988.

The previous prime is 30971951. The next prime is 30972041. The reversal of 30971989 is 98917903.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16402500 + 14569489 = 4050^2 + 3817^2 .

It is a cyclic number.

It is not a de Polignac number, because 30971989 - 2⁹ = 30971477 is a prime.

It is a super-2 number, since 2×30971989² = 1918528205232242, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (30971089) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15485994 + 15485995.

It is an arithmetic number, because the mean of its divisors is an integer number (15485995).

Almost surely, 2^30971989 is an apocalyptic number.

It is an amenable number.

30971989 is a deficient number, since it is larger than the sum of its proper divisors (1).

30971989 is an equidigital number, since it uses as much as digits as its factorization.

30971989 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 122472, while the sum is 46.

The square root of 30971989 is about 5565.2483322849. The cubic root of 30971989 is about 314.0434203684.

The spelling of 30971989 in words is "thirty million, nine hundred seventy-one thousand, nine hundred eighty-nine".