6688890 has 48 divisors (see below), whose sum is σ = 18732168. Its totient is φ = 1646208.

The previous prime is 6688859. The next prime is 6688907. The reversal of 6688890 is 988866.

It can be written as a sum of positive squares in 4 ways, for example, as 4447881 + 2241009 = 2109^2 + 1497^2 .

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1689 + ... + 4028.

Almost surely, 2^6688890 is an apocalyptic number.

6688890 is an abundant number, since it is smaller than the sum of its proper divisors (12043278).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

6688890 is a wasteful number, since it uses less digits than its factorization.

6688890 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5743 (or 5740 counting only the distinct ones).

The product of its (nonzero) digits is 165888, while the sum is 45.

The square root of 6688890 is about 2586.2888469775. The cubic root of 6688890 is about 188.4161034013.

The spelling of 6688890 in words is "six million, six hundred eighty-eight thousand, eight hundred ninety".