1665183561 has 16 divisors (see below), whose sum is σ = 2231410368. Its totient is φ = 1104552000.

The previous prime is 1665183497. The next prime is 1665183581. The reversal of 1665183561 is 1653815661.

It is not a de Polignac number, because 1665183561 - 2⁶ = 1665183497 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1665183581) 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, 1146886 + ... + 1148336.

It is an arithmetic number, because the mean of its divisors is an integer number (139463148).

Almost surely, 2^1665183561 is an apocalyptic number.

It is an amenable number.

1665183561 is a deficient number, since it is larger than the sum of its proper divisors (566226807).

1665183561 is a wasteful number, since it uses less digits than its factorization.

1665183561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3112.

The product of its digits is 129600, while the sum is 42.

The square root of 1665183561 is about 40806.6607430699. The cubic root of 1665183561 is about 1185.2793138874.

The spelling of 1665183561 in words is "one billion, six hundred sixty-five million, one hundred eighty-three thousand, five hundred sixty-one".