161813880 has 192 divisors, whose sum is σ = 568058400. Its totient is φ = 39813120.

The previous prime is 161813833. The next prime is 161813887. The reversal of 161813880 is 88318161.

161813880 is a `hidden beast` number, since 1 + 618 + 1 + 38 + 8 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161813887) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 280152 + ... + 280728.

Almost surely, 2^161813880 is an apocalyptic number.

161813880 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 161813880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (284029200).

161813880 is an abundant number, since it is smaller than the sum of its proper divisors (406244520).

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

161813880 is a wasteful number, since it uses less digits than its factorization.

161813880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 654 (or 647 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 36.

The square root of 161813880 is about 12720.6084760125. The cubic root of 161813880 is about 544.9273308827.

The spelling of 161813880 in words is "one hundred sixty-one million, eight hundred thirteen thousand, eight hundred eighty".