18666007 has 4 divisors (see below), whose sum is σ = 18982440. Its totient is φ = 18349576.

The previous prime is 18665993. The next prime is 18666023. The reversal of 18666007 is 70066681.

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

It is a cyclic number.

It is not a de Polignac number, because 18666007 - 2¹⁵ = 18633239 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18666047) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 158128 + ... + 158245.

It is an arithmetic number, because the mean of its divisors is an integer number (4745610).

Almost surely, 2^18666007 is an apocalyptic number.

18666007 is a deficient number, since it is larger than the sum of its proper divisors (316433).

18666007 is an equidigital number, since it uses as much as digits as its factorization.

18666007 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 316432.

The product of its (nonzero) digits is 12096, while the sum is 34.

The square root of 18666007 is about 4320.4174566817. The cubic root of 18666007 is about 265.2673556665.

The spelling of 18666007 in words is "eighteen million, six hundred sixty-six thousand, seven".