18136819 has 4 divisors (see below), whose sum is σ = 18275400. Its totient is φ = 17998240.

The previous prime is 18136799. The next prime is 18136823. The reversal of 18136819 is 91863181.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 91863181 = 2341 ⋅39241.

It is a cyclic number.

It is not a de Polignac number, because 18136819 - 2¹⁹ = 17612531 is a prime.

It is a super-2 number, since 2×18136819² = 657888406877522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18136889) 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, 69094 + ... + 69355.

It is an arithmetic number, because the mean of its divisors is an integer number (4568850).

Almost surely, 2^18136819 is an apocalyptic number.

18136819 is a deficient number, since it is larger than the sum of its proper divisors (138581).

18136819 is a wasteful number, since it uses less digits than its factorization.

18136819 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 138580.

The product of its digits is 10368, while the sum is 37.

The square root of 18136819 is about 4258.7344364259. The cubic root of 18136819 is about 262.7364774532.

The spelling of 18136819 in words is "eighteen million, one hundred thirty-six thousand, eight hundred nineteen".