165994311 has 12 divisors (see below), whose sum is σ = 257460792. Its totient is φ = 94853808.

The previous prime is 165994303. The next prime is 165994349. The reversal of 165994311 is 113499561.

It is not a de Polignac number, because 165994311 - 2³ = 165994303 is a prime.

It is a super-2 number, since 2×165994311² = 55108222568729442, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 165994311.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165994391) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 564460 + ... + 564753.

It is an arithmetic number, because the mean of its divisors is an integer number (21455066).

Almost surely, 2^165994311 is an apocalyptic number.

165994311 is a deficient number, since it is larger than the sum of its proper divisors (91466481).

165994311 is a wasteful number, since it uses less digits than its factorization.

165994311 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1129230 (or 1129223 counting only the distinct ones).

The product of its digits is 29160, while the sum is 39.

The square root of 165994311 is about 12883.8779488165. The cubic root of 165994311 is about 549.5801876297.

It can be divided in two parts, 16599 and 4311, that added together give a triangular number (20910 = T₂₀₄).

The spelling of 165994311 in words is "one hundred sixty-five million, nine hundred ninety-four thousand, three hundred eleven".