18809863 has 4 divisors (see below), whose sum is σ = 18821968. Its totient is φ = 18797760.

The previous prime is 18809807. The next prime is 18809873. The reversal of 18809863 is 36890881.

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: 36890881 = 757 ⋅48733.

It is a cyclic number.

It is not a de Polignac number, because 18809863 - 2¹⁷ = 18678791 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18809873) 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, 3306 + ... + 6967.

It is an arithmetic number, because the mean of its divisors is an integer number (4705492).

Almost surely, 2^18809863 is an apocalyptic number.

18809863 is a deficient number, since it is larger than the sum of its proper divisors (12105).

18809863 is a wasteful number, since it uses less digits than its factorization.

18809863 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12104.

The product of its (nonzero) digits is 82944, while the sum is 43.

The square root of 18809863 is about 4337.0338942646. The cubic root of 18809863 is about 265.9470705171.

The spelling of 18809863 in words is "eighteen million, eight hundred nine thousand, eight hundred sixty-three".