6688690 has 8 divisors (see below), whose sum is σ = 12039660. Its totient is φ = 2675472.

The previous prime is 6688673. The next prime is 6688691. The reversal of 6688690 is 968866.

It can be written as a sum of positive squares in 2 ways, for example, as 6466849 + 221841 = 2543^2 + 471^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×6688690² = 89477147832200, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (6688691) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 334425 + ... + 334444.

Almost surely, 2^6688690 is an apocalyptic number.

6688690 is a deficient number, since it is larger than the sum of its proper divisors (5350970).

6688690 is a wasteful number, since it uses less digits than its factorization.

6688690 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 668876.

The product of its (nonzero) digits is 124416, while the sum is 43.

The square root of 6688690 is about 2586.2501812470. The cubic root of 6688690 is about 188.4142254815.

The spelling of 6688690 in words is "six million, six hundred eighty-eight thousand, six hundred ninety".