161840961 has 6 divisors (see below), whose sum is σ = 233770290. Its totient is φ = 107893968.

The previous prime is 161840947. The next prime is 161840971. The reversal of 161840961 is 169048161.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 159138225 + 2702736 = 12615^2 + 1644^2 .

It is not a de Polignac number, because 161840961 - 2⁹ = 161840449 is a prime.

It is not an unprimeable number, because it can be changed into a prime (161840971) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 8991156 + ... + 8991173.

It is an arithmetic number, because the mean of its divisors is an integer number (38961715).

Almost surely, 2^161840961 is an apocalyptic number.

It is an amenable number.

161840961 is a deficient number, since it is larger than the sum of its proper divisors (71929329).

161840961 is a wasteful number, since it uses less digits than its factorization.

161840961 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17982335 (or 17982332 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 36.

The square root of 161840961 is about 12721.6728852773. The cubic root of 161840961 is about 544.9577286744.

The spelling of 161840961 in words is "one hundred sixty-one million, eight hundred forty thousand, nine hundred sixty-one".