165406666 has 8 divisors (see below), whose sum is σ = 261168480. Its totient is φ = 78350508.

The previous prime is 165406649. The next prime is 165406667. The reversal of 165406666 is 666604561.

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

It is not an unprimeable number, because it can be changed into a prime (165406667) 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, 2176366 + ... + 2176441.

It is an arithmetic number, because the mean of its divisors is an integer number (32646060).

Almost surely, 2^165406666 is an apocalyptic number.

165406666 is a deficient number, since it is larger than the sum of its proper divisors (95761814).

165406666 is a wasteful number, since it uses less digits than its factorization.

165406666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4352828.

The product of its (nonzero) digits is 155520, while the sum is 40.

The square root of 165406666 is about 12861.0522897623. The cubic root of 165406666 is about 548.9308884549.

The spelling of 165406666 in words is "one hundred sixty-five million, four hundred six thousand, six hundred sixty-six".