18713897 has 4 divisors (see below), whose sum is σ = 19219716. Its totient is φ = 18208080.

The previous prime is 18713869. The next prime is 18713899. The reversal of 18713897 is 79831781.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 79831781 = 23 ⋅3470947.

It can be written as a sum of positive squares in 2 ways, for example, as 17799961 + 913936 = 4219^2 + 956^2 .

It is a cyclic number.

It is not a de Polignac number, because 18713897 - 2¹⁸ = 18451753 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18713899) 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, 252854 + ... + 252927.

It is an arithmetic number, because the mean of its divisors is an integer number (4804929).

Almost surely, 2^18713897 is an apocalyptic number.

It is an amenable number.

18713897 is a deficient number, since it is larger than the sum of its proper divisors (505819).

18713897 is an equidigital number, since it uses as much as digits as its factorization.

18713897 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 505818.

The product of its digits is 84672, while the sum is 44.

The square root of 18713897 is about 4325.9561948776. The cubic root of 18713897 is about 265.4940209061.

The spelling of 18713897 in words is "eighteen million, seven hundred thirteen thousand, eight hundred ninety-seven".