161321984 has 44 divisors (see below), whose sum is σ = 324269364. Its totient is φ = 80216064.

The previous prime is 161321971. The next prime is 161322013. The reversal of 161321984 is 489123161.

It can be written as a sum of positive squares in 2 ways, for example, as 75203584 + 86118400 = 8672^2 + 9280^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 262862 + ... + 263474.

Almost surely, 2^161321984 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 161321984, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (162134682).

161321984 is an abundant number, since it is smaller than the sum of its proper divisors (162947380).

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

161321984 is an equidigital number, since it uses as much as digits as its factorization.

161321984 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 890 (or 872 counting only the distinct ones).

The product of its digits is 10368, while the sum is 35.

The square root of 161321984 is about 12701.2591501788. The cubic root of 161321984 is about 544.3745978178.

The spelling of 161321984 in words is "one hundred sixty-one million, three hundred twenty-one thousand, nine hundred eighty-four".