161780644 has 12 divisors (see below), whose sum is σ = 283355100. Its totient is φ = 80822048.

The previous prime is 161780609. The next prime is 161780657. The reversal of 161780644 is 446087161.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 151782400 + 9998244 = 12320^2 + 3162^2 .

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, 11539 + ... + 21370.

It is an arithmetic number, because the mean of its divisors is an integer number (23612925).

Almost surely, 2^161780644 is an apocalyptic number.

It is an amenable number.

161780644 is a deficient number, since it is larger than the sum of its proper divisors (121574456).

161780644 is a wasteful number, since it uses less digits than its factorization.

161780644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34142 (or 34140 counting only the distinct ones).

The product of its (nonzero) digits is 32256, while the sum is 37.

The square root of 161780644 is about 12719.3020248754. The cubic root of 161780644 is about 544.8900196110.

The spelling of 161780644 in words is "one hundred sixty-one million, seven hundred eighty thousand, six hundred forty-four".