18868868497 has 4 divisors (see below), whose sum is σ = 19978801956. Its totient is φ = 17758935040.

The previous prime is 18868868477. The next prime is 18868868507. The reversal of 18868868497 is 79486886881.

It is a Cunningham number, because it is equal to 137364²+1.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 79486886881 = 58661 ⋅1355021.

It can be written as a sum of positive squares in 2 ways, for example, as 14690409616 + 4178458881 = 121204^2 + 64641^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18868868497 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18868868477) 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, 554966704 + ... + 554966737.

It is an arithmetic number, because the mean of its divisors is an integer number (4994700489).

Almost surely, 2^18868868497 is an apocalyptic number.

18868868497 is a gapful number since it is divisible by the number (17) formed by its first and last digit.

It is an amenable number.

18868868497 is a deficient number, since it is larger than the sum of its proper divisors (1109933459).

18868868497 is a wasteful number, since it uses less digits than its factorization.

18868868497 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1109933458.

The product of its digits is 297271296, while the sum is 73.

The spelling of 18868868497 in words is "eighteen billion, eight hundred sixty-eight million, eight hundred sixty-eight thousand, four hundred ninety-seven".