6990660 has 72 divisors (see below), whose sum is σ = 21542976. Its totient is φ = 1834560.

The previous prime is 6990629. The next prime is 6990667. The reversal of 6990660 is 660996.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an Ulam number.

It is not an unprimeable number, because it can be changed into a prime (6990667) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 12507 + ... + 13053.

It is an arithmetic number, because the mean of its divisors is an integer number (299208).

Almost surely, 2^6990660 is an apocalyptic number.

6990660 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 6990660, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (10771488).

6990660 is an abundant number, since it is smaller than the sum of its proper divisors (14552316).

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

6990660 is a wasteful number, since it uses less digits than its factorization.

6990660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 633 (or 628 counting only the distinct ones).

The product of its (nonzero) digits is 17496, while the sum is 36.

The square root of 6990660 is about 2643.9856277975. The cubic root of 6990660 is about 191.2080005172.

The spelling of 6990660 in words is "six million, nine hundred ninety thousand, six hundred sixty".