161005845 has 64 divisors (see below), whose sum is σ = 345913344. Its totient is φ = 61758720.

The previous prime is 161005841. The next prime is 161005849. The reversal of 161005845 is 548500161.

It is an interprime number because it is at equal distance from previous prime (161005841) and next prime (161005849).

It is not a de Polignac number, because 161005845 - 2² = 161005841 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161005841) by changing a digit.

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 63 ways as a sum of consecutive naturals, for example, 9654 + ... + 20376.

It is an arithmetic number, because the mean of its divisors is an integer number (5404896).

Almost surely, 2^161005845 is an apocalyptic number.

161005845 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

161005845 is an abundant number, since it is smaller than the sum of its proper divisors (184907499).

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

161005845 is a wasteful number, since it uses less digits than its factorization.

161005845 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10762.

The product of its (nonzero) digits is 4800, while the sum is 30.

The square root of 161005845 is about 12688.8078636253. The cubic root of 161005845 is about 544.0187657976.

It can be divided in two parts, 16100 and 5845, that added together give a triangular number (21945 = T₂₀₉).

The spelling of 161005845 in words is "one hundred sixty-one million, five thousand, eight hundred forty-five".