30991938847 has 4 divisors (see below), whose sum is σ = 30992590440. Its totient is φ = 30991287256.

The previous prime is 30991938821. The next prime is 30991938877. The reversal of 30991938847 is 74883919903.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-30991938847 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (30991938877) 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, 248308 + ... + 351625.

It is an arithmetic number, because the mean of its divisors is an integer number (7748147610).

Almost surely, 2^30991938847 is an apocalyptic number.

30991938847 is a deficient number, since it is larger than the sum of its proper divisors (651593).

30991938847 is an equidigital number, since it uses as much as digits as its factorization.

30991938847 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 651592.

The product of its (nonzero) digits is 11757312, while the sum is 61.

The spelling of 30991938847 in words is "thirty billion, nine hundred ninety-one million, nine hundred thirty-eight thousand, eight hundred forty-seven".