161561106 has 24 divisors (see below), whose sum is σ = 400056384. Its totient is φ = 46160280.

The previous prime is 161561093. The next prime is 161561111. The reversal of 161561106 is 601165161.

It is a super-2 number, since 2×161561106² = 52203981943886472, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 161561106.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 640990 + ... + 641241.

It is an arithmetic number, because the mean of its divisors is an integer number (16669016).

Almost surely, 2^161561106 is an apocalyptic number.

161561106 is an abundant number, since it is smaller than the sum of its proper divisors (238495278).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

161561106 is a wasteful number, since it uses less digits than its factorization.

161561106 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1282246 (or 1282243 counting only the distinct ones).

The product of its (nonzero) digits is 1080, while the sum is 27.

The square root of 161561106 is about 12710.6689831810. The cubic root of 161561106 is about 544.6434342483.

The spelling of 161561106 in words is "one hundred sixty-one million, five hundred sixty-one thousand, one hundred six".