165800000 has 84 divisors (see below), whose sum is σ = 411731460. Its totient is φ = 66240000.

The previous prime is 165799967. The next prime is 165800017. The reversal of 165800000 is 8561.

It can be written as a sum of positive squares in 6 ways, for example, as 131974144 + 33825856 = 11488^2 + 5816^2 .

It is a Harshad number since it is a multiple of its sum of digits (20).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 199586 + ... + 200414.

It is an arithmetic number, because the mean of its divisors is an integer number (4901565).

Almost surely, 2^165800000 is an apocalyptic number.

165800000 is a gapful number since it is divisible by the number (10) 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 165800000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (205865730).

165800000 is an abundant number, since it is smaller than the sum of its proper divisors (245931460).

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

165800000 is an frugal number, since it uses more digits than its factorization.

165800000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 866 (or 836 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 20.

The square root of 165800000 is about 12876.3348822559. The cubic root of 165800000 is about 549.3656598523.

Adding to 165800000 its reverse (8561), we get a palindrome (165808561).

The spelling of 165800000 in words is "one hundred sixty-five million, eight hundred thousand".