6986640 has 80 divisors (see below), whose sum is σ = 22195008. Its totient is φ = 1817088.

The previous prime is 6986627. The next prime is 6986647. The reversal of 6986640 is 466896.

It is a tau number, because it is divible by the number of its divisors (80).

It is an Ulam number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6986647) 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 15 ways as a sum of consecutive naturals, for example, 9982 + ... + 10658.

Almost surely, 2^6986640 is an apocalyptic number.

6986640 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 6986640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (11097504).

6986640 is an abundant number, since it is smaller than the sum of its proper divisors (15208368).

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

6986640 is a wasteful number, since it uses less digits than its factorization.

6986640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 736 (or 730 counting only the distinct ones).

The product of its (nonzero) digits is 62208, while the sum is 39.

The square root of 6986640 is about 2643.2253025423. The cubic root of 6986640 is about 191.1713419114.

It can be divided in two parts, 6986 and 640, that added together give a triangular number (7626 = T₁₂₃).

The spelling of 6986640 in words is "six million, nine hundred eighty-six thousand, six hundred forty".