689555856025 has 27 divisors (see below), whose sum is σ = 902523663453. Its totient is φ = 522550965600.

The previous prime is 689555856013. The next prime is 689555856061. The reversal of 689555856025 is 520658555986.

The square root of 689555856025 is 830395.

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

It can be written as a sum of positive squares in 4 ways, for example, as 149895188569 + 539660667456 = 387163^2 + 734616^2 .

It is a de Polignac number, because none of the positive numbers 2^k-689555856025 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 78883155 + ... + 78891895.

Almost surely, 2^689555856025 is an apocalyptic number.

689555856025 is the 830395-th square number.

689555856025 is the 415198-th centered octagonal number.

It is an amenable number.

689555856025 is a deficient number, since it is larger than the sum of its proper divisors (212967807428).

689555856025 is an frugal number, since it uses more digits than its factorization.

689555856025 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17530 (or 8765 counting only the distinct ones).

The product of its (nonzero) digits is 129600000, while the sum is 64.

Multiplying 689555856025 by its sum of digits (64), we get a square (44131574785600 = 6643160²).

The spelling of 689555856025 in words is "six hundred eighty-nine billion, five hundred fifty-five million, eight hundred fifty-six thousand, twenty-five".