1661605441 has 16 divisors (see below), whose sum is σ = 1731457728. Its totient is φ = 1593446400.

The previous prime is 1661605417. The next prime is 1661605447. The reversal of 1661605441 is 1445061661.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1661605441 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1661605397 and 1661605406.

It is not an unprimeable number, because it can be changed into a prime (1661605447) 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 15 ways as a sum of consecutive naturals, for example, 544881 + ... + 547921.

It is an arithmetic number, because the mean of its divisors is an integer number (108216108).

Almost surely, 2^1661605441 is an apocalyptic number.

It is an amenable number.

1661605441 is a deficient number, since it is larger than the sum of its proper divisors (69852287).

1661605441 is a wasteful number, since it uses less digits than its factorization.

1661605441 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3312.

The product of its (nonzero) digits is 17280, while the sum is 34.

The square root of 1661605441 is about 40762.7948134080. The cubic root of 1661605441 is about 1184.4297352853.

The spelling of 1661605441 in words is "one billion, six hundred sixty-one million, six hundred five thousand, four hundred forty-one".