18106999 has 4 divisors (see below), whose sum is σ = 18528136. Its totient is φ = 17685864.

The previous prime is 18106997. The next prime is 18107009. The reversal of 18106999 is 99960181.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 99960181 = 67 ⋅1491943.

It is a cyclic number.

It is not a de Polignac number, because 18106999 - 2¹ = 18106997 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (43), and also a Moran number because the ratio is a prime number: 421093 = 18106999 / (1 + 8 + 1 + 0 + 6 + 9 + 9 + 9).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18106997) 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, 210504 + ... + 210589.

It is an arithmetic number, because the mean of its divisors is an integer number (4632034).

Almost surely, 2^18106999 is an apocalyptic number.

18106999 is a deficient number, since it is larger than the sum of its proper divisors (421137).

18106999 is an equidigital number, since it uses as much as digits as its factorization.

18106999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 421136.

The product of its (nonzero) digits is 34992, while the sum is 43.

The square root of 18106999 is about 4255.2319560748. The cubic root of 18106999 is about 262.5924040521.

The spelling of 18106999 in words is "eighteen million, one hundred six thousand, nine hundred ninety-nine".