165990771 has 48 divisors (see below), whose sum is σ = 265973760. Its totient is φ = 99290880.

The previous prime is 165990757. The next prime is 165990779. The reversal of 165990771 is 177099561.

It is not a de Polignac number, because 165990771 - 2⁹ = 165990259 is a prime.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (165990779) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 374476 + ... + 374918.

It is an arithmetic number, because the mean of its divisors is an integer number (5541120).

Almost surely, 2^165990771 is an apocalyptic number.

165990771 is a deficient number, since it is larger than the sum of its proper divisors (99982989).

165990771 is a wasteful number, since it uses less digits than its factorization.

165990771 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 576 (or 573 counting only the distinct ones).

The product of its (nonzero) digits is 119070, while the sum is 45.

The square root of 165990771 is about 12883.7405670869. The cubic root of 165990771 is about 549.5762808137.

The spelling of 165990771 in words is "one hundred sixty-five million, nine hundred ninety thousand, seven hundred seventy-one".