18190861 has 16 divisors (see below), whose sum is σ = 20716416. Its totient is φ = 15846336.

The previous prime is 18190841. The next prime is 18190883. The reversal of 18190861 is 16809181.

It is a cyclic number.

It is not a de Polignac number, because 18190861 - 2¹⁹ = 17666573 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 (18190811) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 24451 + ... + 25183.

It is an arithmetic number, because the mean of its divisors is an integer number (1294776).

Almost surely, 2^18190861 is an apocalyptic number.

It is an amenable number.

18190861 is a deficient number, since it is larger than the sum of its proper divisors (2525555).

18190861 is a wasteful number, since it uses less digits than its factorization.

18190861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 852.

The product of its (nonzero) digits is 3456, while the sum is 34.

The square root of 18190861 is about 4265.0745597234. The cubic root of 18190861 is about 262.9971759686.

The spelling of 18190861 in words is "eighteen million, one hundred ninety thousand, eight hundred sixty-one".