161782920 has 320 divisors, whose sum is σ = 614718720. Its totient is φ = 37863936.

The previous prime is 161782903. The next prime is 161782927. The reversal of 161782920 is 29287161.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (161782927) 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 79 ways as a sum of consecutive naturals, for example, 968677 + ... + 968843.

It is an arithmetic number, because the mean of its divisors is an integer number (1920996).

Almost surely, 2^161782920 is an apocalyptic number.

161782920 is a gapful number since it is divisible by the number (10) 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 161782920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (307359360).

161782920 is an abundant number, since it is smaller than the sum of its proper divisors (452935800).

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

161782920 is a wasteful number, since it uses less digits than its factorization.

161782920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 226 (or 213 counting only the distinct ones).

The product of its (nonzero) digits is 12096, while the sum is 36.

The square root of 161782920 is about 12719.3914948790. The cubic root of 161782920 is about 544.8925748484.

The spelling of 161782920 in words is "one hundred sixty-one million, seven hundred eighty-two thousand, nine hundred twenty".