18216841 has 4 divisors (see below), whose sum is σ = 18241300. Its totient is φ = 18192384.

The previous prime is 18216823. The next prime is 18216853. The reversal of 18216841 is 14861281.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 14861281 = 17 ⋅874193.

It can be written as a sum of positive squares in 2 ways, for example, as 2975625 + 15241216 = 1725^2 + 3904^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18216841 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18216811) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11076 + ... + 12613.

It is an arithmetic number, because the mean of its divisors is an integer number (4560325).

Almost surely, 2^18216841 is an apocalyptic number.

It is an amenable number.

18216841 is a deficient number, since it is larger than the sum of its proper divisors (24459).

18216841 is an equidigital number, since it uses as much as digits as its factorization.

18216841 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24458.

The product of its digits is 3072, while the sum is 31.

The square root of 18216841 is about 4268.1191407926. The cubic root of 18216841 is about 263.1223196956.

The spelling of 18216841 in words is "eighteen million, two hundred sixteen thousand, eight hundred forty-one".