161781764 has 12 divisors (see below), whose sum is σ = 283630284. Its totient is φ = 80744544.

The previous prime is 161781743. The next prime is 161781769. The reversal of 161781764 is 467187161.

161781764 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 67108864 + 94672900 = 8192^2 + 9730^2 .

It is not an unprimeable number, because it can be changed into a prime (161781769) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 34079 + ... + 38534.

It is an arithmetic number, because the mean of its divisors is an integer number (23635857).

Almost surely, 2^161781764 is an apocalyptic number.

It is an amenable number.

161781764 is a deficient number, since it is larger than the sum of its proper divisors (121848520).

161781764 is a wasteful number, since it uses less digits than its factorization.

161781764 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 73174 (or 73172 counting only the distinct ones).

The product of its digits is 56448, while the sum is 41.

The square root of 161781764 is about 12719.3460523723. The cubic root of 161781764 is about 544.8912770243.

The spelling of 161781764 in words is "one hundred sixty-one million, seven hundred eighty-one thousand, seven hundred sixty-four".