1666977109 has 24 divisors (see below), whose sum is σ = 2057396760. Its totient is φ = 1342043136.

The previous prime is 1666977089. The next prime is 1666977113. The reversal of 1666977109 is 9017796661.

It can be written as a sum of positive squares in 4 ways, for example, as 607474609 + 1059502500 = 24647^2 + 32550^2 .

It is not a de Polignac number, because 1666977109 - 2⁵ = 1666977077 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1666977409) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 472219 + ... + 475735.

It is an arithmetic number, because the mean of its divisors is an integer number (85724865).

Almost surely, 2^1666977109 is an apocalyptic number.

It is an amenable number.

1666977109 is a deficient number, since it is larger than the sum of its proper divisors (390419651).

1666977109 is a wasteful number, since it uses less digits than its factorization.

1666977109 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4117 (or 4110 counting only the distinct ones).

The product of its (nonzero) digits is 857304, while the sum is 52.

The square root of 1666977109 is about 40828.6309959078. The cubic root of 1666977109 is about 1185.7047109437.

The spelling of 1666977109 in words is "one billion, six hundred sixty-six million, nine hundred seventy-seven thousand, one hundred nine".