18849309971 has 4 divisors (see below), whose sum is σ = 18852004752. Its totient is φ = 18846615192.

The previous prime is 18849309959. The next prime is 18849309979. The reversal of 18849309971 is 17990394881.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 17990394881 = 20593 ⋅873617.

It is a cyclic number.

It is not a de Polignac number, because 18849309971 - 2¹⁸ = 18849047827 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 18849309971.

It is not an unprimeable number, because it can be changed into a prime (18849309979) 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, 1336871 + ... + 1350896.

It is an arithmetic number, because the mean of its divisors is an integer number (4713001188).

Almost surely, 2^18849309971 is an apocalyptic number.

18849309971 is a deficient number, since it is larger than the sum of its proper divisors (2694781).

18849309971 is an equidigital number, since it uses as much as digits as its factorization.

18849309971 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2694780.

The product of its (nonzero) digits is 3919104, while the sum is 59.

The spelling of 18849309971 in words is "eighteen billion, eight hundred forty-nine million, three hundred nine thousand, nine hundred seventy-one".