18243857 has 12 divisors (see below), whose sum is σ = 19490436. Its totient is φ = 17072640.

The previous prime is 18243851. The next prime is 18243877. The reversal of 18243857 is 75834281.

It can be written as a sum of positive squares in 2 ways, for example, as 6677056 + 11566801 = 2584^2 + 3401^2 .

It is not a de Polignac number, because 18243857 - 2⁶ = 18243793 is a prime.

It is a Duffinian number.

It is a zygodrome in base 16.

It is a self number, because there is not a number n which added to its sum of digits gives 18243857.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18243851) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 34757 + ... + 35277.

It is an arithmetic number, because the mean of its divisors is an integer number (1624203).

Almost surely, 2^18243857 is an apocalyptic number.

It is an amenable number.

18243857 is a deficient number, since it is larger than the sum of its proper divisors (1246579).

18243857 is an equidigital number, since it uses as much as digits as its factorization.

18243857 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 656 (or 637 counting only the distinct ones).

The product of its digits is 53760, while the sum is 38.

The square root of 18243857 is about 4271.2828283784. The cubic root of 18243857 is about 263.2523276271.

The spelling of 18243857 in words is "eighteen million, two hundred forty-three thousand, eight hundred fifty-seven".