18099861 has 24 divisors (see below), whose sum is σ = 26714016. Its totient is φ = 10836000.

The previous prime is 18099853. The next prime is 18099869. The reversal of 18099861 is 16899081.

It is an interprime number because it is at equal distance from previous prime (18099853) and next prime (18099869).

It is not a de Polignac number, because 18099861 - 2³ = 18099853 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18099869) 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 23 ways as a sum of consecutive naturals, for example, 71986 + ... + 72236.

It is an arithmetic number, because the mean of its divisors is an integer number (1113084).

Almost surely, 2^18099861 is an apocalyptic number.

It is an amenable number.

18099861 is a deficient number, since it is larger than the sum of its proper divisors (8614155).

18099861 is a wasteful number, since it uses less digits than its factorization.

18099861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 353 (or 310 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 42.

The square root of 18099861 is about 4254.3931412130. The cubic root of 18099861 is about 262.5578938067.

The spelling of 18099861 in words is "eighteen million, ninety-nine thousand, eight hundred sixty-one".