18115385 has 16 divisors (see below), whose sum is σ = 22490832. Its totient is φ = 13996800.

The previous prime is 18115381. The next prime is 18115403. The reversal of 18115385 is 58351181.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 984064 + 17131321 = 992^2 + 4139^2 .

It is not a de Polignac number, because 18115385 - 2² = 18115381 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (18115381) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 33215 + ... + 33755.

It is an arithmetic number, because the mean of its divisors is an integer number (1405677).

Almost surely, 2^18115385 is an apocalyptic number.

It is an amenable number.

18115385 is a deficient number, since it is larger than the sum of its proper divisors (4375447).

18115385 is a wasteful number, since it uses less digits than its factorization.

18115385 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 764.

The product of its digits is 4800, while the sum is 32.

The square root of 18115385 is about 4256.2172172012. The cubic root of 18115385 is about 262.6329364456.

The spelling of 18115385 in words is "eighteen million, one hundred fifteen thousand, three hundred eighty-five".