16688764225 has 27 divisors (see below), whose sum is σ = 24079214691. Its totient is φ = 11440623600.

The previous prime is 16688764219. The next prime is 16688764231. The reversal of 16688764225 is 52246788661.

The square root of 16688764225 is 129185.

It is a perfect power (a square), and thus also a powerful number.

16688764225 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (16688764219) and next prime (16688764231).

It can be written as a sum of positive squares in only one way, i.e., 6007955121 + 10680809104 = 77511^2 + 103348^2 .

It is not a de Polignac number, because 16688764225 - 2²⁵ = 16655209793 is a prime.

It is an unprimeable number.

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 in 26 ways as a sum of consecutive naturals, for example, 4519630 + ... + 4523320.

Almost surely, 2^16688764225 is an apocalyptic number.

16688764225 is the 129185-th square number.

16688764225 is the 64593-rd centered octagonal number.

It is an amenable number.

16688764225 is a deficient number, since it is larger than the sum of its proper divisors (7390450466).

16688764225 is an frugal number, since it uses more digits than its factorization.

16688764225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7406 (or 3703 counting only the distinct ones).

The product of its digits is 7741440, while the sum is 55.

The spelling of 16688764225 in words is "sixteen billion, six hundred eighty-eight million, seven hundred sixty-four thousand, two hundred twenty-five".