18959987899 has 4 divisors (see below), whose sum is σ = 18960705360. Its totient is φ = 18959270440.

The previous prime is 18959987897. The next prime is 18959987929. The reversal of 18959987899 is 99878995981.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 99878995981 = 26597 ⋅3755273.

It is a cyclic number.

It is not a de Polignac number, because 18959987899 - 2¹ = 18959987897 is a prime.

It is a super-2 number, since 2×18959987899² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18959987897) 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, 317512 + ... + 372469.

It is an arithmetic number, because the mean of its divisors is an integer number (4740176340).

Almost surely, 2^18959987899 is an apocalyptic number.

18959987899 is a deficient number, since it is larger than the sum of its proper divisors (717461).

18959987899 is an equidigital number, since it uses as much as digits as its factorization.

18959987899 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 717460.

The product of its digits is 1058158080, while the sum is 82.

The spelling of 18959987899 in words is "eighteen billion, nine hundred fifty-nine million, nine hundred eighty-seven thousand, eight hundred ninety-nine".