161130661 has 4 divisors (see below), whose sum is σ = 161217324. Its totient is φ = 161044000.

The previous prime is 161130649. The next prime is 161130679. The reversal of 161130661 is 166031161.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 166031161 = 1039 ⋅159799.

It can be written as a sum of positive squares in 2 ways, for example, as 32421636 + 128709025 = 5694^2 + 11345^2 .

It is a cyclic number.

It is not a de Polignac number, because 161130661 - 2¹¹ = 161128613 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161130961) 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 in 3 ways as a sum of consecutive naturals, for example, 40480 + ... + 44281.

It is an arithmetic number, because the mean of its divisors is an integer number (40304331).

Almost surely, 2^161130661 is an apocalyptic number.

It is an amenable number.

161130661 is a deficient number, since it is larger than the sum of its proper divisors (86663).

161130661 is an equidigital number, since it uses as much as digits as its factorization.

161130661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 86662.

The product of its (nonzero) digits is 648, while the sum is 25.

The square root of 161130661 is about 12693.7252609311. The cubic root of 161130661 is about 544.1593087435.

The spelling of 161130661 in words is "one hundred sixty-one million, one hundred thirty thousand, six hundred sixty-one".