165638753280 has 3168 divisors, whose sum is σ = 856218504960. Its totient is φ = 30098718720.

The previous prime is 165638753249. The next prime is 165638753317. The reversal of 165638753280 is 82357836561.

165638753280 is a `hidden beast` number, since 1 + 6 + 563 + 8 + 7 + 53 + 28 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (3168).

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

It is an unprimeable number.

It is a polite number, since it can be written in 287 ways as a sum of consecutive naturals, for example, 8717829111 + ... + 8717829129.

Almost surely, 2^165638753280 is an apocalyptic number.

165638753280 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 165638753280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (428109252480).

165638753280 is an abundant number, since it is smaller than the sum of its proper divisors (690579751680).

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

165638753280 is a wasteful number, since it uses less digits than its factorization.

165638753280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 97 (or 60 counting only the distinct ones).

The product of its (nonzero) digits is 7257600, while the sum is 54.

The spelling of 165638753280 in words is "one hundred sixty-five billion, six hundred thirty-eight million, seven hundred fifty-three thousand, two hundred eighty".