165778812 has 60 divisors (see below), whose sum is σ = 436272760. Its totient is φ = 54890784.

The previous prime is 165778777. The next prime is 165778817. The reversal of 165778812 is 218877561.

It is a happy number.

165778812 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×165778812² = 54965229016262688, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165778817) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 49239 + ... + 52497.

Almost surely, 2^165778812 is an apocalyptic number.

165778812 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 165778812, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (218136380).

165778812 is an abundant number, since it is smaller than the sum of its proper divisors (270493948).

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

165778812 is a wasteful number, since it uses less digits than its factorization.

165778812 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3432 (or 3421 counting only the distinct ones).

The product of its digits is 188160, while the sum is 45.

The square root of 165778812 is about 12875.5121063203. The cubic root of 165778812 is about 549.3422572479.

The spelling of 165778812 in words is "one hundred sixty-five million, seven hundred seventy-eight thousand, eight hundred twelve".