165987800 has 144 divisors (see below), whose sum is σ = 447757800. Its totient is φ = 57182400.

The previous prime is 165987763. The next prime is 165987817. The reversal of 165987800 is 8789561.

It is a happy number.

It is a powerful number, because all its prime factors have an exponent greater than 1 and also an Achilles number because it is not a perfect power.

165987800 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (44).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 8736191 + ... + 8736209.

Almost surely, 2^165987800 is an apocalyptic number.

165987800 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 165987800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (223878900).

165987800 is an abundant number, since it is smaller than the sum of its proper divisors (281770000).

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

165987800 is a wasteful number, since it uses less digits than its factorization.

165987800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 95 (or 37 counting only the distinct ones).

The product of its (nonzero) digits is 120960, while the sum is 44.

The square root of 165987800 is about 12883.6252662052. The cubic root of 165987800 is about 549.5730019148.

The spelling of 165987800 in words is "one hundred sixty-five million, nine hundred eighty-seven thousand, eight hundred".