2177979689 has 2 divisors, whose sum is σ = 2177979690. Its totient is φ = 2177979688.

The previous prime is 2177979647. The next prime is 2177979761. The reversal of 2177979689 is 9869797712.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1626105625 + 551874064 = 40325^2 + 23492^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2177979689 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (2177979619) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1088989844 + 1088989845.

It is an arithmetic number, because the mean of its divisors is an integer number (1088989845).

Almost surely, 2^2177979689 is an apocalyptic number.

It is an amenable number.

2177979689 is a deficient number, since it is larger than the sum of its proper divisors (1).

2177979689 is an equidigital number, since it uses as much as digits as its factorization.

2177979689 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 24004512, while the sum is 65.

The square root of 2177979689 is about 46668.8299510498. The cubic root of 2177979689 is about 1296.2375807982.

The spelling of 2177979689 in words is "two billion, one hundred seventy-seven million, nine hundred seventy-nine thousand, six hundred eighty-nine".