1666939305 has 32 divisors (see below), whose sum is σ = 2754746496. Its totient is φ = 860281344.

The previous prime is 1666939303. The next prime is 1666939327. The reversal of 1666939305 is 5039396661.

It is not a de Polignac number, because 1666939305 - 2¹ = 1666939303 is a prime.

It is a Smith number, since the sum of its digits (48) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (1666939303) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 43674 + ... + 72396.

It is an arithmetic number, because the mean of its divisors is an integer number (86085828).

Almost surely, 2^1666939305 is an apocalyptic number.

1666939305 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1666939305 is a deficient number, since it is larger than the sum of its proper divisors (1087807191).

1666939305 is a wasteful number, since it uses less digits than its factorization.

1666939305 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28857.

The product of its (nonzero) digits is 787320, while the sum is 48.

The square root of 1666939305 is about 40828.1680338464. The cubic root of 1666939305 is about 1185.6957476693.

The spelling of 1666939305 in words is "one billion, six hundred sixty-six million, nine hundred thirty-nine thousand, three hundred five".