161100561 has 16 divisors (see below), whose sum is σ = 219127616. Its totient is φ = 105255936.

The previous prime is 161100559. The next prime is 161100581. The reversal of 161100561 is 165001161.

It is not a de Polignac number, because 161100561 - 2¹ = 161100559 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (161100581) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 33441 + ... + 37953.

It is an arithmetic number, because the mean of its divisors is an integer number (13695476).

Almost surely, 2^161100561 is an apocalyptic number.

It is an amenable number.

161100561 is a deficient number, since it is larger than the sum of its proper divisors (58027055).

161100561 is a wasteful number, since it uses less digits than its factorization.

161100561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4752.

The product of its (nonzero) digits is 180, while the sum is 21.

The square root of 161100561 is about 12692.5395803992. The cubic root of 161100561 is about 544.1254227550.

The spelling of 161100561 in words is "one hundred sixty-one million, one hundred thousand, five hundred sixty-one".