18664147 has 4 divisors (see below), whose sum is σ = 19762056. Its totient is φ = 17566240.

The previous prime is 18664073. The next prime is 18664153. The reversal of 18664147 is 74146681.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 74146681 = 7 ⋅10592383.

It is a cyclic number.

It is not a de Polignac number, because 18664147 - 2¹⁹ = 18139859 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18664157) 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 3 ways as a sum of consecutive naturals, for example, 548929 + ... + 548962.

It is an arithmetic number, because the mean of its divisors is an integer number (4940514).

Almost surely, 2^18664147 is an apocalyptic number.

18664147 is a gapful number since it is divisible by the number (17) formed by its first and last digit.

18664147 is a deficient number, since it is larger than the sum of its proper divisors (1097909).

18664147 is a wasteful number, since it uses less digits than its factorization.

18664147 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1097908.

The product of its digits is 32256, while the sum is 37.

The square root of 18664147 is about 4320.2021943423. The cubic root of 18664147 is about 265.2585443967.

The spelling of 18664147 in words is "eighteen million, six hundred sixty-four thousand, one hundred forty-seven".