18982081 has 4 divisors (see below), whose sum is σ = 20098692. Its totient is φ = 17865472.

The previous prime is 18982043. The next prime is 18982087. The reversal of 18982081 is 18028981.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 9734400 + 9247681 = 3120^2 + 3041^2 .

It is a cyclic number.

It is not a de Polignac number, because 18982081 - 2⁷ = 18981953 is a prime.

It is a super-2 number, since 2×18982081² = 720638798181122, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 18982081.

It is not an unprimeable number, because it can be changed into a prime (18982087) 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, 558280 + ... + 558313.

It is an arithmetic number, because the mean of its divisors is an integer number (5024673).

Almost surely, 2^18982081 is an apocalyptic number.

It is an amenable number.

18982081 is a deficient number, since it is larger than the sum of its proper divisors (1116611).

18982081 is a wasteful number, since it uses less digits than its factorization.

18982081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1116610.

The product of its (nonzero) digits is 9216, while the sum is 37.

The square root of 18982081 is about 4356.8430084179. The cubic root of 18982081 is about 266.7562523659.

The spelling of 18982081 in words is "eighteen million, nine hundred eighty-two thousand, eighty-one".