18871297 has 4 divisors (see below), whose sum is σ = 18998100. Its totient is φ = 18744496.

The previous prime is 18871291. The next prime is 18871301. The reversal of 18871297 is 79217881.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 79217881 = 53 ⋅1494677.

It can be written as a sum of positive squares in 2 ways, for example, as 2298256 + 16573041 = 1516^2 + 4071^2 .

It is a cyclic number.

It is not a de Polignac number, because 18871297 - 2¹⁵ = 18838529 is a prime.

It is a super-2 number, since 2×18871297² = 712251700924418, which contains 22 as substring.

It is a pancake number, because a pancake can be divided into 18871297 parts by 6143 straight cuts.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18871291) 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, 63178 + ... + 63475.

It is an arithmetic number, because the mean of its divisors is an integer number (4749525).

Almost surely, 2^18871297 is an apocalyptic number.

It is an amenable number.

18871297 is a deficient number, since it is larger than the sum of its proper divisors (126803).

18871297 is a wasteful number, since it uses less digits than its factorization.

18871297 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 126802.

The product of its digits is 56448, while the sum is 43.

The square root of 18871297 is about 4344.1106109306. The cubic root of 18871297 is about 266.2362882430.

The spelling of 18871297 in words is "eighteen million, eight hundred seventy-one thousand, two hundred ninety-seven".