18309285 has 12 divisors (see below), whose sum is σ = 31736172. Its totient is φ = 9764928.

The previous prime is 18309283. The next prime is 18309287. The reversal of 18309285 is 58290381.

It is an interprime number because it is at equal distance from previous prime (18309283) and next prime (18309287).

It can be written as a sum of positive squares in 2 ways, for example, as 8964036 + 9345249 = 2994^2 + 3057^2 .

It is not a de Polignac number, because 18309285 - 2¹ = 18309283 is a prime.

It is a super-2 number, since 2×18309285² = 670459834422450, which contains 22 as substring.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18309283) by changing a digit.

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 11 ways as a sum of consecutive naturals, for example, 203392 + ... + 203481.

It is an arithmetic number, because the mean of its divisors is an integer number (2644681).

Almost surely, 2^18309285 is an apocalyptic number.

18309285 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

18309285 is a deficient number, since it is larger than the sum of its proper divisors (13426887).

18309285 is a wasteful number, since it uses less digits than its factorization.

18309285 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 406884 (or 406881 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 36.

The square root of 18309285 is about 4278.9350310562. The cubic root of 18309285 is about 263.5666530457.

It can be divided in two parts, 18309 and 285, that multiplied together give a triangular number (5218065 = T₃₂₃₀).

The spelling of 18309285 in words is "eighteen million, three hundred nine thousand, two hundred eighty-five".