166665215 has 8 divisors (see below), whose sum is σ = 200216448. Its totient is φ = 133186720.

The previous prime is 166665203. The next prime is 166665281. The reversal of 166665215 is 512566661.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 166665215 - 2⁶ = 166665151 is a prime.

It is a Duffinian 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, 13007 + ... + 22416.

It is an arithmetic number, because the mean of its divisors is an integer number (25027056).

Almost surely, 2^166665215 is an apocalyptic number.

166665215 is a deficient number, since it is larger than the sum of its proper divisors (33551233).

166665215 is an equidigital number, since it uses as much as digits as its factorization.

166665215 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36369.

The product of its digits is 64800, while the sum is 38.

The square root of 166665215 is about 12909.8882644274. Note that the first 3 decimals coincide. The cubic root of 166665215 is about 550.3196103786.

The spelling of 166665215 in words is "one hundred sixty-six million, six hundred sixty-five thousand, two hundred fifteen".