165299408640 has 324 divisors, whose sum is σ = 593915608104. Its totient is φ = 44079842304.

The previous prime is 165299408629. The next prime is 165299408647. The reversal of 165299408640 is 46804992561.

165299408640 is a `hidden beast` number, since 16 + 529 + 9 + 40 + 8 + 64 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (324).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165299408647) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 33059881726 + ... + 33059881730.

Almost surely, 2^165299408640 is an apocalyptic number.

165299408640 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 165299408640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (296957804052).

165299408640 is an abundant number, since it is smaller than the sum of its proper divisors (428616199464).

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

165299408640 is an frugal number, since it uses more digits than its factorization.

165299408640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 72 (or 10 counting only the distinct ones).

The product of its (nonzero) digits is 3732480, while the sum is 54.

The spelling of 165299408640 in words is "one hundred sixty-five billion, two hundred ninety-nine million, four hundred eight thousand, six hundred forty".