18211642 has 16 divisors (see below), whose sum is σ = 27862272. Its totient is φ = 8925840.

The previous prime is 18211637. The next prime is 18211643. The reversal of 18211642 is 24611281.

It is not an unprimeable number, because it can be changed into a prime (18211643) by changing a digit.

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 in 7 ways as a sum of consecutive naturals, for example, 39103 + ... + 39565.

It is an arithmetic number, because the mean of its divisors is an integer number (1741392).

Almost surely, 2^18211642 is an apocalyptic number.

18211642 is a deficient number, since it is larger than the sum of its proper divisors (9650630).

18211642 is a wasteful number, since it uses less digits than its factorization.

18211642 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 813.

The product of its digits is 768, while the sum is 25.

The square root of 18211642 is about 4267.5100468540. The cubic root of 18211642 is about 263.0972860267.

The spelling of 18211642 in words is "eighteen million, two hundred eleven thousand, six hundred forty-two".