161661180 has 48 divisors (see below), whose sum is σ = 460333440. Its totient is φ = 42378048.

The previous prime is 161661161. The next prime is 161661191. The reversal of 161661180 is 81166161.

It is a happy number.

It is a super-3 number, since 3×161661180³ (a number of 26 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 19294 + ... + 26373.

It is an arithmetic number, because the mean of its divisors is an integer number (9590280).

Almost surely, 2^161661180 is an apocalyptic number.

161661180 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

161661180 is an abundant number, since it is smaller than the sum of its proper divisors (298672260).

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

161661180 is a wasteful number, since it uses less digits than its factorization.

161661180 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45738 (or 45736 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 30.

The square root of 161661180 is about 12714.6049879656. The cubic root of 161661180 is about 544.7558651804.

The spelling of 161661180 in words is "one hundred sixty-one million, six hundred sixty-one thousand, one hundred eighty".