1666643299 has 2 divisors, whose sum is σ = 1666643300. Its totient is φ = 1666643298.

The previous prime is 1666643261. The next prime is 1666643327. The reversal of 1666643299 is 9923466661.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1666643299 - 2¹⁵ = 1666610531 is a prime.

It is a super-2 number, since 2×1666643299² = 5555399772203206802, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1666683299) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 833321649 + 833321650.

It is an arithmetic number, because the mean of its divisors is an integer number (833321650).

Almost surely, 2^1666643299 is an apocalyptic number.

1666643299 is a deficient number, since it is larger than the sum of its proper divisors (1).

1666643299 is an equidigital number, since it uses as much as digits as its factorization.

1666643299 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2519424, while the sum is 52.

The square root of 1666643299 is about 40824.5428510841. The cubic root of 1666643299 is about 1185.6255603843.

The spelling of 1666643299 in words is "one billion, six hundred sixty-six million, six hundred forty-three thousand, two hundred ninety-nine".