161243784 has 80 divisors (see below), whose sum is σ = 486398220. Its totient is φ = 49610880.

The previous prime is 161243729. The next prime is 161243791. The reversal of 161243784 is 487342161.

161243784 is a `hidden beast` number, since 1 + 612 + 4 + 37 + 8 + 4 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 156500100 + 4743684 = 12510^2 + 2178^2 .

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

It is an unprimeable number.

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 19 ways as a sum of consecutive naturals, for example, 1147 + ... + 17994.

Almost surely, 2^161243784 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 161243784, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (243199110).

161243784 is an abundant number, since it is smaller than the sum of its proper divisors (325154436).

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

161243784 is a wasteful number, since it uses less digits than its factorization.

161243784 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19172 (or 19159 counting only the distinct ones).

The product of its digits is 32256, while the sum is 36.

The square root of 161243784 is about 12698.1803420805. The cubic root of 161243784 is about 544.2866226746.

The spelling of 161243784 in words is "one hundred sixty-one million, two hundred forty-three thousand, seven hundred eighty-four".