18521018 has 8 divisors (see below), whose sum is σ = 27803412. Its totient is φ = 9253216.

The previous prime is 18520993. The next prime is 18521021. The reversal of 18521018 is 81012581.

It can be written as a sum of positive squares in 2 ways, for example, as 13667809 + 4853209 = 3697^2 + 2203^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is an alternating number because its digits alternate between odd and even.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 446 + ... + 6102.

Almost surely, 2^18521018 is an apocalyptic number.

18521018 is a deficient number, since it is larger than the sum of its proper divisors (9282394).

18521018 is a wasteful number, since it uses less digits than its factorization.

18521018 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7296.

The product of its (nonzero) digits is 640, while the sum is 26.

The square root of 18521018 is about 4303.6052328251. The cubic root of 18521018 is about 264.5787444978.

Adding to 18521018 its reverse (81012581), we get a palindrome (99533599).

The spelling of 18521018 in words is "eighteen million, five hundred twenty-one thousand, eighteen".