19666166 has 16 divisors (see below), whose sum is σ = 32628624. Its totient is φ = 8830944.

The previous prime is 19666151. The next prime is 19666201. The reversal of 19666166 is 66166691.

It is a happy number.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9260 + ... + 11183.

It is an arithmetic number, because the mean of its divisors is an integer number (2039289).

Almost surely, 2^19666166 is an apocalyptic number.

19666166 is a deficient number, since it is larger than the sum of its proper divisors (12962458).

19666166 is a wasteful number, since it uses less digits than its factorization.

19666166 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20495.

The product of its digits is 69984, while the sum is 41.

The square root of 19666166 is about 4434.6551162407. The cubic root of 19666166 is about 269.9230050233.

The spelling of 19666166 in words is "nineteen million, six hundred sixty-six thousand, one hundred sixty-six".