6690840 has 64 divisors (see below), whose sum is σ = 21621600. Its totient is φ = 1646592.

The previous prime is 6690829. The next prime is 6690847. The reversal of 6690840 is 480966.

It is a zygodrome in base 2.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6690847) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 585 + ... + 3704.

Almost surely, 2^6690840 is an apocalyptic number.

6690840 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 6690840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (10810800).

6690840 is an abundant number, since it is smaller than the sum of its proper divisors (14930760).

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

6690840 is a wasteful number, since it uses less digits than its factorization.

6690840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4316 (or 4312 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 33.

The square root of 6690840 is about 2586.6658075600. The cubic root of 6690840 is about 188.4344111576.

The spelling of 6690840 in words is "six million, six hundred ninety thousand, eight hundred forty".