165217409280 has 864 divisors, whose sum is σ = 750274237440. Its totient is φ = 32520683520.

The previous prime is 165217409263. The next prime is 165217409309. The reversal of 165217409280 is 82904712561.

165217409280 is a `hidden beast` number, since 1 + 6 + 5 + 217 + 409 + 28 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 16848859 + ... + 16858661.

It is an arithmetic number, because the mean of its divisors is an integer number (868372960).

Almost surely, 2^165217409280 is an apocalyptic number.

165217409280 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 165217409280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (375137118720).

165217409280 is an abundant number, since it is smaller than the sum of its proper divisors (585056828160).

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

165217409280 is a wasteful number, since it uses less digits than its factorization.

165217409280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9867 (or 9850 counting only the distinct ones).

The product of its (nonzero) digits is 241920, while the sum is 45.

The spelling of 165217409280 in words is "one hundred sixty-five billion, two hundred seventeen million, four hundred nine thousand, two hundred eighty".