161921382 has 128 divisors (see below), whose sum is σ = 411264000. Its totient is φ = 42336000.

The previous prime is 161921369. The next prime is 161921407. The reversal of 161921382 is 283129161.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1603132 + ... + 1603232.

It is an arithmetic number, because the mean of its divisors is an integer number (3213000).

Almost surely, 2^161921382 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 161921382, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (205632000).

161921382 is an abundant number, since it is smaller than the sum of its proper divisors (249342618).

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

161921382 is a wasteful number, since it uses less digits than its factorization.

161921382 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 187 (or 173 counting only the distinct ones).

The product of its digits is 5184, while the sum is 33.

The square root of 161921382 is about 12724.8332798509. The cubic root of 161921382 is about 545.0479793913.

The spelling of 161921382 in words is "one hundred sixty-one million, nine hundred twenty-one thousand, three hundred eighty-two".