30991019 has 2 divisors, whose sum is σ = 30991020. Its totient is φ = 30991018.

The previous prime is 30991013. The next prime is 30991031. The reversal of 30991019 is 91019903.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-30991019 is a prime.

It is a super-2 number, since 2×30991019² = 1920886517316722, which contains 22 as substring.

It is a Chen prime.

It is equal to p_1915457 and since 30991019 and 1915457 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (30991013) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15495509 + 15495510.

It is an arithmetic number, because the mean of its divisors is an integer number (15495510).

Almost surely, 2^30991019 is an apocalyptic number.

30991019 is a deficient number, since it is larger than the sum of its proper divisors (1).

30991019 is an equidigital number, since it uses as much as digits as its factorization.

30991019 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2187, while the sum is 32.

The square root of 30991019 is about 5566.9577867988. The cubic root of 30991019 is about 314.1077260299.

The spelling of 30991019 in words is "thirty million, nine hundred ninety-one thousand, nineteen".