6688993490 has 32 divisors (see below), whose sum is σ = 12139397424. Its totient is φ = 2653588480.

The previous prime is 6688993481. The next prime is 6688993511. The reversal of 6688993490 is 943998866.

It can be written as a sum of positive squares in 8 ways, for example, as 2027790961 + 4661202529 = 45031^2 + 68273^2 .

It is a Curzon number.

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 15 ways as a sum of consecutive naturals, for example, 2356352 + ... + 2359188.

Almost surely, 2^6688993490 is an apocalyptic number.

6688993490 is a deficient number, since it is larger than the sum of its proper divisors (5450403934).

6688993490 is a wasteful number, since it uses less digits than its factorization.

6688993490 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4702.

The product of its (nonzero) digits is 20155392, while the sum is 62.

The square root of 6688993490 is about 81786.2671235214. The cubic root of 6688993490 is about 1884.1707511616.

The spelling of 6688993490 in words is "six billion, six hundred eighty-eight million, nine hundred ninety-three thousand, four hundred ninety".