165219840 has 240 divisors, whose sum is σ = 586007136. Its totient is φ = 43008000.

The previous prime is 165219799. The next prime is 165219841. The reversal of 165219840 is 48912561.

165219840 is a `hidden beast` number, since 1 + 6 + 521 + 98 + 40 = 666.

It is a tau number, because it is divible by the number of its divisors (240).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 165219795 and 165219804.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165219841) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1635790 + ... + 1635890.

Almost surely, 2^165219840 is an apocalyptic number.

165219840 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 165219840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (293003568).

165219840 is an abundant number, since it is smaller than the sum of its proper divisors (420787296).

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

165219840 is a wasteful number, since it uses less digits than its factorization.

165219840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 201 (or 182 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 36.

The square root of 165219840 is about 12853.7869906110. The cubic root of 165219840 is about 548.7241390324.

The spelling of 165219840 in words is "one hundred sixty-five million, two hundred nineteen thousand, eight hundred forty".