18098261 has 4 divisors (see below), whose sum is σ = 18539724. Its totient is φ = 17656800.

The previous prime is 18098257. The next prime is 18098287. The reversal of 18098261 is 16289081.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 16289081 = 1423 ⋅11447.

It can be written as a sum of positive squares in 2 ways, for example, as 5317636 + 12780625 = 2306^2 + 3575^2 .

It is a cyclic number.

It is not a de Polignac number, because 18098261 - 2² = 18098257 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18098221) 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, 220670 + ... + 220751.

It is an arithmetic number, because the mean of its divisors is an integer number (4634931).

Almost surely, 2^18098261 is an apocalyptic number.

It is an amenable number.

18098261 is a deficient number, since it is larger than the sum of its proper divisors (441463).

18098261 is an equidigital number, since it uses as much as digits as its factorization.

18098261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 441462.

The product of its (nonzero) digits is 6912, while the sum is 35.

The square root of 18098261 is about 4254.2050961372. The cubic root of 18098261 is about 262.5501570068.

The spelling of 18098261 in words is "eighteen million, ninety-eight thousand, two hundred sixty-one".