18659897 has 8 divisors (see below), whose sum is σ = 19808712. Its totient is φ = 17516800.

The previous prime is 18659891. The next prime is 18659899. The reversal of 18659897 is 79895681.

It can be written as a sum of positive squares in 4 ways, for example, as 92416 + 18567481 = 304^2 + 4309^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 18659897 - 2²⁴ = 1882681 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18659891) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6647 + ... + 9027.

It is an arithmetic number, because the mean of its divisors is an integer number (2476089).

Almost surely, 2^18659897 is an apocalyptic number.

18659897 is a gapful number since it is divisible by the number (17) formed by its first and last digit.

It is an amenable number.

18659897 is a deficient number, since it is larger than the sum of its proper divisors (1148815).

18659897 is a wasteful number, since it uses less digits than its factorization.

18659897 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2859.

The product of its digits is 1088640, while the sum is 53.

The square root of 18659897 is about 4319.7102912117. The cubic root of 18659897 is about 265.2384089218.

The spelling of 18659897 in words is "eighteen million, six hundred fifty-nine thousand, eight hundred ninety-seven".