30945991 has 2 divisors, whose sum is σ = 30945992. Its totient is φ = 30945990.

The previous prime is 30945983. The next prime is 30946009. The reversal of 30945991 is 19954903.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 30945991 - 2³ = 30945983 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (30945911) 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, 15472995 + 15472996.

It is an arithmetic number, because the mean of its divisors is an integer number (15472996).

Almost surely, 2^30945991 is an apocalyptic number.

30945991 is a deficient number, since it is larger than the sum of its proper divisors (1).

30945991 is an equidigital number, since it uses as much as digits as its factorization.

30945991 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 43740, while the sum is 40.

The square root of 30945991 is about 5562.9120970945. The cubic root of 30945991 is about 313.9555260419.

The spelling of 30945991 in words is "thirty million, nine hundred forty-five thousand, nine hundred ninety-one".