16666139 has 4 divisors (see below), whose sum is σ = 19047024. Its totient is φ = 14285256.

The previous prime is 16666093. The next prime is 16666141. The reversal of 16666139 is 93166661.

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: 93166661 = 7 ⋅13309523.

It is a cyclic number.

It is not a de Polignac number, because 16666139 - 2¹² = 16662043 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16666159) 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, 1190432 + ... + 1190445.

It is an arithmetic number, because the mean of its divisors is an integer number (4761756).

Almost surely, 2^16666139 is an apocalyptic number.

16666139 is a deficient number, since it is larger than the sum of its proper divisors (2380885).

16666139 is an equidigital number, since it uses as much as digits as its factorization.

16666139 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2380884.

The product of its digits is 34992, while the sum is 38.

The square root of 16666139 is about 4082.4182784227. The cubic root of 16666139 is about 255.4337817298.

The spelling of 16666139 in words is "sixteen million, six hundred sixty-six thousand, one hundred thirty-nine".