18619966 has 4 divisors (see below), whose sum is σ = 27929952. Its totient is φ = 9309982.

The previous prime is 18619921. The next prime is 18619969. The reversal of 18619966 is 66991681.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 66991681 = 2243 ⋅29867.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18619969) 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 as a sum of consecutive naturals, namely, 4654990 + ... + 4654993.

It is an arithmetic number, because the mean of its divisors is an integer number (6982488).

Almost surely, 2^18619966 is an apocalyptic number.

18619966 is a deficient number, since it is larger than the sum of its proper divisors (9309986).

18619966 is an equidigital number, since it uses as much as digits as its factorization.

18619966 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9309985.

The product of its digits is 139968, while the sum is 46.

The square root of 18619966 is about 4315.0858624134. The cubic root of 18619966 is about 265.0490759946.

The spelling of 18619966 in words is "eighteen million, six hundred nineteen thousand, nine hundred sixty-six".