18081019 has 4 divisors (see below), whose sum is σ = 19724760. Its totient is φ = 16437280.

The previous prime is 18080999. The next prime is 18081023. The reversal of 18081019 is 91018081.

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

It is a cyclic number.

It is not a de Polignac number, because 18081019 - 2¹³ = 18072827 is a prime.

It is a super-3 number, since 3×18081019³ (a number of 23 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is not an unprimeable number, because it can be changed into a prime (18081079) 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, 821854 + ... + 821875.

It is an arithmetic number, because the mean of its divisors is an integer number (4931190).

Almost surely, 2^18081019 is an apocalyptic number.

18081019 is a deficient number, since it is larger than the sum of its proper divisors (1643741).

18081019 is a wasteful number, since it uses less digits than its factorization.

18081019 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1643740.

The product of its (nonzero) digits is 576, while the sum is 28.

The square root of 18081019 is about 4252.1781477262. The cubic root of 18081019 is about 262.4667543686.

The spelling of 18081019 in words is "eighteen million, eighty-one thousand, nineteen".