2166715687 has 2 divisors, whose sum is σ = 2166715688. Its totient is φ = 2166715686.

The previous prime is 2166715633. The next prime is 2166715717. The reversal of 2166715687 is 7865176612.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 2166715687 - 2¹⁵ = 2166682919 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 2166715687.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2166715387) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1083357843 + 1083357844.

It is an arithmetic number, because the mean of its divisors is an integer number (1083357844).

Almost surely, 2^2166715687 is an apocalyptic number.

2166715687 is a deficient number, since it is larger than the sum of its proper divisors (1).

2166715687 is an equidigital number, since it uses as much as digits as its factorization.

2166715687 is an evil number, because the sum of its binary digits is even.

The product of its digits is 846720, while the sum is 49.

The square root of 2166715687 is about 46547.9933724323. The cubic root of 2166715687 is about 1293.9991047726. Note that the first 3 decimals are identical.

The spelling of 2166715687 in words is "two billion, one hundred sixty-six million, seven hundred fifteen thousand, six hundred eighty-seven".