1666161599 has 2 divisors, whose sum is σ = 1666161600. Its totient is φ = 1666161598.

The previous prime is 1666161577. The next prime is 1666161617. The reversal of 1666161599 is 9951616661.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1666161599 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1666161559) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 833080799 + 833080800.

It is an arithmetic number, because the mean of its divisors is an integer number (833080800).

Almost surely, 2^1666161599 is an apocalyptic number.

1666161599 is a deficient number, since it is larger than the sum of its proper divisors (1).

1666161599 is an equidigital number, since it uses as much as digits as its factorization.

1666161599 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 524880, while the sum is 50.

The square root of 1666161599 is about 40818.6427873343. The cubic root of 1666161599 is about 1185.5113246100.

The spelling of 1666161599 in words is "one billion, six hundred sixty-six million, one hundred sixty-one thousand, five hundred ninety-nine".