161840656 has 10 divisors (see below), whose sum is σ = 313566302. Its totient is φ = 80920320.

The previous prime is 161840647. The next prime is 161840659. The reversal of 161840656 is 656048161.

It can be written as a sum of positive squares in only one way, i.e., 91011600 + 70829056 = 9540^2 + 8416^2 .

It is not an unprimeable number, because it can be changed into a prime (161840659) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5057505 + ... + 5057536.

Almost surely, 2^161840656 is an apocalyptic number.

161840656 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

161840656 is a deficient number, since it is larger than the sum of its proper divisors (151725646).

161840656 is a wasteful number, since it uses less digits than its factorization.

161840656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10115049 (or 10115043 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 37.

The square root of 161840656 is about 12721.6608978545. The cubic root of 161840656 is about 544.9573863379.

The spelling of 161840656 in words is "one hundred sixty-one million, eight hundred forty thousand, six hundred fifty-six".