18106538 has 4 divisors (see below), whose sum is σ = 27159810. Its totient is φ = 9053268.

The previous prime is 18106537. The next prime is 18106567. The reversal of 18106538 is 83560181.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 83560181 = 307 ⋅272183.

It can be written as a sum of positive squares in only one way, i.e., 16265089 + 1841449 = 4033^2 + 1357^2 .

It is a plaindrome in base 16.

It is not an unprimeable number, because it can be changed into a prime (18106531) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4526633 + ... + 4526636.

Almost surely, 2^18106538 is an apocalyptic number.

18106538 is a deficient number, since it is larger than the sum of its proper divisors (9053272).

18106538 is an equidigital number, since it uses as much as digits as its factorization.

18106538 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9053271.

The product of its (nonzero) digits is 5760, while the sum is 32.

The square root of 18106538 is about 4255.1777871201. The cubic root of 18106538 is about 262.5901755192.

The spelling of 18106538 in words is "eighteen million, one hundred six thousand, five hundred thirty-eight".