6687690807249 has 27 divisors (see below), whose sum is σ = 10261860972987. Its totient is φ = 4196115399744.

The previous prime is 6687690807223. The next prime is 6687690807251. The reversal of 6687690807249 is 9427080967866.

The square root of 6687690807249 is 2586057.

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

It can be written as a sum of positive squares in only one way, i.e., 5206679694225 + 1481011113024 = 2281815^2 + 1216968^2 .

It is not a de Polignac number, because 6687690807249 - 2²⁵ = 6687657252817 is a prime.

It is not an unprimeable number, because it can be changed into a prime (6687690807209) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 131863554 + ... + 131914260.

Almost surely, 2^{6687690807249} is an apocalyptic number.

6687690807249 is the 2586057-th square number.

6687690807249 is the 1293029-th centered octagonal number.

It is an amenable number.

6687690807249 is a deficient number, since it is larger than the sum of its proper divisors (3574170165738).

6687690807249 is an frugal number, since it uses more digits than its factorization.

6687690807249 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 101454 (or 50727 counting only the distinct ones).

The product of its (nonzero) digits is 438939648, while the sum is 72.

The spelling of 6687690807249 in words is "six trillion, six hundred eighty-seven billion, six hundred ninety million, eight hundred seven thousand, two hundred forty-nine".