165993906 has 32 divisors (see below), whose sum is σ = 358182720. Its totient is φ = 50981184.

The previous prime is 165993901. The next prime is 165993913. The reversal of 165993906 is 609399561.

It is not an unprimeable number, because it can be changed into a prime (165993901) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 49305 + ... + 52563.

It is an arithmetic number, because the mean of its divisors is an integer number (11193210).

Almost surely, 2^165993906 is an apocalyptic number.

165993906 is an abundant number, since it is smaller than the sum of its proper divisors (192188814).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

165993906 is a wasteful number, since it uses less digits than its factorization.

165993906 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3930.

The product of its (nonzero) digits is 393660, while the sum is 48.

The square root of 165993906 is about 12883.8622314894. The cubic root of 165993906 is about 549.5797406663.

The spelling of 165993906 in words is "one hundred sixty-five million, nine hundred ninety-three thousand, nine hundred six".