18905897 has 4 divisors (see below), whose sum is σ = 18915156. Its totient is φ = 18896640.

The previous prime is 18905869. The next prime is 18905923. The reversal of 18905897 is 79850981.

It is a happy number.

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: 79850981 = 7 ⋅11407283.

It can be written as a sum of positive squares in 2 ways, for example, as 16777216 + 2128681 = 4096^2 + 1459^2 .

It is a cyclic number.

It is not a de Polignac number, because 18905897 - 2⁸ = 18905641 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18905867) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 68 + ... + 6149.

It is an arithmetic number, because the mean of its divisors is an integer number (4728789).

Almost surely, 2^18905897 is an apocalyptic number.

It is an amenable number.

18905897 is a deficient number, since it is larger than the sum of its proper divisors (9259).

18905897 is an equidigital number, since it uses as much as digits as its factorization.

18905897 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9258.

The product of its (nonzero) digits is 181440, while the sum is 47.

The square root of 18905897 is about 4348.0911903961. The cubic root of 18905897 is about 266.3989011864.

The spelling of 18905897 in words is "eighteen million, nine hundred five thousand, eight hundred ninety-seven".