18211442 has 4 divisors (see below), whose sum is σ = 27317166. Its totient is φ = 9105720.

The previous prime is 18211439. The next prime is 18211463. The reversal of 18211442 is 24411281.

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., 18139081 + 72361 = 4259^2 + 269^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4552859 + ... + 4552862.

Almost surely, 2^18211442 is an apocalyptic number.

18211442 is a deficient number, since it is larger than the sum of its proper divisors (9105724).

18211442 is an equidigital number, since it uses as much as digits as its factorization.

18211442 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9105723.

The product of its digits is 512, while the sum is 23.

The square root of 18211442 is about 4267.4866139216. The cubic root of 18211442 is about 263.0963229129.

The spelling of 18211442 in words is "eighteen million, two hundred eleven thousand, four hundred forty-two".