161882172 has 48 divisors (see below), whose sum is σ = 425464480. Its totient is φ = 53218944.

The previous prime is 161882159. The next prime is 161882173. The reversal of 161882172 is 271288161.

It is a super-2 number, since 2×161882172² = 52411675222875168, which contains 22 as substring.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

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 (161882173) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2383 + ... + 18150.

Almost surely, 2^161882172 is an apocalyptic number.

161882172 is a gapful number since it is divisible by the number (12) 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 161882172, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (212732240).

161882172 is an abundant number, since it is smaller than the sum of its proper divisors (263582308).

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

161882172 is a wasteful number, since it uses less digits than its factorization.

161882172 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20619 (or 20611 counting only the distinct ones).

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

The square root of 161882172 is about 12723.2924984062. The cubic root of 161882172 is about 545.0039805562.

The spelling of 161882172 in words is "one hundred sixty-one million, eight hundred eighty-two thousand, one hundred seventy-two".