30905993 has 2 divisors, whose sum is σ = 30905994. Its totient is φ = 30905992.

The previous prime is 30905957. The next prime is 30905999. The reversal of 30905993 is 39950903.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 26296384 + 4609609 = 5128^2 + 2147^2 .

It is a cyclic number.

It is not a de Polignac number, because 30905993 - 2⁸ = 30905737 is a prime.

It is not a weakly prime, because it can be changed into another prime (30905999) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15452996 + 15452997.

It is an arithmetic number, because the mean of its divisors is an integer number (15452997).

Almost surely, 2^30905993 is an apocalyptic number.

It is an amenable number.

30905993 is a deficient number, since it is larger than the sum of its proper divisors (1).

30905993 is an equidigital number, since it uses as much as digits as its factorization.

30905993 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 32805, while the sum is 38.

The square root of 30905993 is about 5559.3158751774. The cubic root of 30905993 is about 313.8202041807.

The spelling of 30905993 in words is "thirty million, nine hundred five thousand, nine hundred ninety-three".