18090715 has 4 divisors (see below), whose sum is σ = 21708864. Its totient is φ = 14472568.

The previous prime is 18090697. The next prime is 18090727. The reversal of 18090715 is 51709081.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 18090715 - 2²¹ = 15993563 is a prime.

It is a super-2 number, since 2×18090715² = 654547938422450, which contains 22 as substring.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is an unprimeable number.

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, 1809067 + ... + 1809076.

It is an arithmetic number, because the mean of its divisors is an integer number (5427216).

Almost surely, 2^18090715 is an apocalyptic number.

18090715 is a deficient number, since it is larger than the sum of its proper divisors (3618149).

18090715 is an equidigital number, since it uses as much as digits as its factorization.

18090715 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3618148.

The product of its (nonzero) digits is 2520, while the sum is 31.

The square root of 18090715 is about 4253.3181164827. The cubic root of 18090715 is about 262.5136621763.

Adding to 18090715 its reverse (51709081), we get a palindrome (69799796).

The spelling of 18090715 in words is "eighteen million, ninety thousand, seven hundred fifteen".