30918037993 has 4 divisors (see below), whose sum is σ = 30920896080. Its totient is φ = 30915179908.

The previous prime is 30918037987. The next prime is 30918037999. The reversal of 30918037993 is 39973081903.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 39973081903 = 17 ⋅2351357759.

It is an interprime number because it is at equal distance from previous prime (30918037987) and next prime (30918037999).

It is a cyclic number.

It is not a de Polignac number, because 30918037993 - 2²⁵ = 30884483561 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 30918037993.

It is not an unprimeable number, because it can be changed into a prime (30918037999) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1412755 + ... + 1434472.

It is an arithmetic number, because the mean of its divisors is an integer number (7730224020).

Almost surely, 2^30918037993 is an apocalyptic number.

It is an amenable number.

30918037993 is a deficient number, since it is larger than the sum of its proper divisors (2858087).

30918037993 is a wasteful number, since it uses less digits than its factorization.

30918037993 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2858086.

The product of its (nonzero) digits is 1102248, while the sum is 52.

The spelling of 30918037993 in words is "thirty billion, nine hundred eighteen million, thirty-seven thousand, nine hundred ninety-three".