1666680619 has 2 divisors, whose sum is σ = 1666680620. Its totient is φ = 1666680618.

The previous prime is 1666680607. The next prime is 1666680637. The reversal of 1666680619 is 9160866661.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1666680619 - 2²¹ = 1664583467 is a prime.

It is a super-2 number, since 2×1666680619² = 5555648571500446322, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1666680649) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 833340309 + 833340310.

It is an arithmetic number, because the mean of its divisors is an integer number (833340310).

Almost surely, 2^1666680619 is an apocalyptic number.

1666680619 is a deficient number, since it is larger than the sum of its proper divisors (1).

1666680619 is an equidigital number, since it uses as much as digits as its factorization.

1666680619 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 559872, while the sum is 49.

The square root of 1666680619 is about 40824.9999265156. Note that the first 4 decimals coincide. The cubic root of 1666680619 is about 1185.6344099515.

The spelling of 1666680619 in words is "one billion, six hundred sixty-six million, six hundred eighty thousand, six hundred nineteen".