161822178 has 64 divisors (see below), whose sum is σ = 416256000. Its totient is φ = 45641232.

The previous prime is 161822161. The next prime is 161822179. The reversal of 161822178 is 871228161.

161822178 is a `hidden beast` number, since 1 + 618 + 22 + 17 + 8 = 666.

161822178 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (161822179) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 27153 + ... + 32571.

It is an arithmetic number, because the mean of its divisors is an integer number (6504000).

Almost surely, 2^161822178 is an apocalyptic number.

161822178 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 161822178, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (208128000).

161822178 is an abundant number, since it is smaller than the sum of its proper divisors (254433822).

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

161822178 is a wasteful number, since it uses less digits than its factorization.

161822178 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5516 (or 5510 counting only the distinct ones).

The product of its digits is 10752, while the sum is 36.

The square root of 161822178 is about 12720.9346354739. The cubic root of 161822178 is about 544.9366455548.

The spelling of 161822178 in words is "one hundred sixty-one million, eight hundred twenty-two thousand, one hundred seventy-eight".