18859312897 has 4 divisors (see below), whose sum is σ = 18859593220. Its totient is φ = 18859032576.

The previous prime is 18859312877. The next prime is 18859312903. The reversal of 18859312897 is 79821395881.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 79821395881 = 19 ⋅4201126099.

It can be written as a sum of positive squares in 2 ways, for example, as 1404675441 + 17454637456 = 37479^2 + 132116^2 .

It is a 3-Lehmer number, since φ(18859312897) divides (18859312897-1)³.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18859312897 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18859312807) 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, 28033 + ... + 196225.

It is an arithmetic number, because the mean of its divisors is an integer number (4714898305).

It is a Poulet number, since it divides 2^18859312896-1.

Almost surely, 2^18859312897 is an apocalyptic number.

18859312897 is the 112129-th pentagonal number.

It is an amenable number.

18859312897 is a deficient number, since it is larger than the sum of its proper divisors (280323).

18859312897 is a wasteful number, since it uses less digits than its factorization.

18859312897 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 280322.

The product of its digits is 8709120, while the sum is 61.

The spelling of 18859312897 in words is "eighteen billion, eight hundred fifty-nine million, three hundred twelve thousand, eight hundred ninety-seven".