18749717985 has 16 divisors (see below), whose sum is σ = 30422079360. Its totient is φ = 9859006080.

The previous prime is 18749717981. The next prime is 18749717989. The reversal of 18749717985 is 58971794781.

It is an interprime number because it is at equal distance from previous prime (18749717981) and next prime (18749717989).

It is not a de Polignac number, because 18749717985 - 2² = 18749717981 is a prime.

It is not an unprimeable number, because it can be changed into a prime (18749717981) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8801620 + ... + 8803749.

It is an arithmetic number, because the mean of its divisors is an integer number (1901379960).

Almost surely, 2^18749717985 is an apocalyptic number.

18749717985 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

18749717985 is a deficient number, since it is larger than the sum of its proper divisors (11672361375).

18749717985 is a wasteful number, since it uses less digits than its factorization.

18749717985 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17605448.

The product of its digits is 35562240, while the sum is 66.

The spelling of 18749717985 in words is "eighteen billion, seven hundred forty-nine million, seven hundred seventeen thousand, nine hundred eighty-five".