18021434 has 4 divisors (see below), whose sum is σ = 27032154. Its totient is φ = 9010716.

The previous prime is 18021407. The next prime is 18021449. The reversal of 18021434 is 43412081.

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

It can be written as a sum of positive squares in only one way, i.e., 14799409 + 3222025 = 3847^2 + 1795^2 .

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4505357 + ... + 4505360.

Almost surely, 2^18021434 is an apocalyptic number.

18021434 is a deficient number, since it is larger than the sum of its proper divisors (9010720).

18021434 is an equidigital number, since it uses as much as digits as its factorization.

18021434 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9010719.

The product of its (nonzero) digits is 768, while the sum is 23.

The square root of 18021434 is about 4245.1659567089. The cubic root of 18021434 is about 262.1781221788.

The spelling of 18021434 in words is "eighteen million, twenty-one thousand, four hundred thirty-four".