18209057 has 4 divisors (see below), whose sum is σ = 19280196. Its totient is φ = 17137920.

The previous prime is 18209033. The next prime is 18209063. The reversal of 18209057 is 75090281.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 75090281 = 7 ⋅10727183.

It can be written as a sum of positive squares in 2 ways, for example, as 9541921 + 8667136 = 3089^2 + 2944^2 .

It is a cyclic number.

It is not a de Polignac number, because 18209057 - 2²⁴ = 1431841 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18209027) 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 3 ways as a sum of consecutive naturals, for example, 535544 + ... + 535577.

It is an arithmetic number, because the mean of its divisors is an integer number (4820049).

Almost surely, 2^18209057 is an apocalyptic number.

18209057 is a gapful number since it is divisible by the number (17) formed by its first and last digit.

It is an amenable number.

18209057 is a deficient number, since it is larger than the sum of its proper divisors (1071139).

18209057 is a wasteful number, since it uses less digits than its factorization.

18209057 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1071138.

The product of its (nonzero) digits is 5040, while the sum is 32.

The square root of 18209057 is about 4267.2071662857. The cubic root of 18209057 is about 263.0848372377.

The spelling of 18209057 in words is "eighteen million, two hundred nine thousand, fifty-seven".