165640860 has 576 divisors, whose sum is σ = 717050880. Its totient is φ = 29859840.

The previous prime is 165640771. The next prime is 165640873. The reversal of 165640860 is 68046561.

165640860 is a `hidden beast` number, since 1 + 6 + 5 + 640 + 8 + 6 + 0 = 666.

165640860 is digitally balanced in base 3 and base 9, because in such bases 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 (36).

165640860 is strictly pandigital in base 9.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 4476762 + ... + 4476798.

It is an arithmetic number, because the mean of its divisors is an integer number (1244880).

Almost surely, 2^165640860 is an apocalyptic number.

165640860 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 165640860, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (358525440).

165640860 is an abundant number, since it is smaller than the sum of its proper divisors (551410020).

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

165640860 is a wasteful number, since it uses less digits than its factorization.

165640860 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 106 (or 101 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 36.

The square root of 165640860 is about 12870.1538452343. The cubic root of 165640860 is about 549.1898375012.

The spelling of 165640860 in words is "one hundred sixty-five million, six hundred forty thousand, eight hundred sixty".