165863551140 has 144 divisors (see below), whose sum is σ = 575690868480. Its totient is φ = 37865698560.

The previous prime is 165863551093. The next prime is 165863551151. The reversal of 165863551140 is 41155368561.

It is a happy number.

165863551140 is a `hidden beast` number, since 1 + 6 + 5 + 8 + 635 + 5 + 1 + 1 + 4 + 0 = 666.

165863551140 is digitally balanced in base 2, because in such base 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 (45).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 965145 + ... + 1123935.

Almost surely, 2^165863551140 is an apocalyptic number.

165863551140 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 165863551140, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (287845434240).

165863551140 is an abundant number, since it is smaller than the sum of its proper divisors (409827317340).

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

165863551140 is a wasteful number, since it uses less digits than its factorization.

165863551140 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 159642 (or 159637 counting only the distinct ones).

The product of its (nonzero) digits is 432000, while the sum is 45.

It can be divided in two parts, 165863 and 551140, that added together give a triangular number (717003 = T₁₁₉₇).

The spelling of 165863551140 in words is "one hundred sixty-five billion, eight hundred sixty-three million, five hundred fifty-one thousand, one hundred forty".