6864640 has 72 divisors (see below), whose sum is σ = 17071488. Its totient is φ = 2641920.

The previous prime is 6864631. The next prime is 6864653. The reversal of 6864640 is 464686.

It is a nialpdrome in base 14.

It is a junction number, because it is equal to n+sod(n) for n = 6864596 and 6864605.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 39594 + ... + 39766.

It is an arithmetic number, because the mean of its divisors is an integer number (237104).

Almost surely, 2^6864640 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 6864640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (8535744).

6864640 is an abundant number, since it is smaller than the sum of its proper divisors (10206848).

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

6864640 is a wasteful number, since it uses less digits than its factorization.

6864640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 225 (or 211 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 34.

The square root of 6864640 is about 2620.0458011264. The cubic root of 6864640 is about 190.0520632948.

It can be divided in two parts, 68646 and 40, that added together give a palindrome (68686).

The spelling of 6864640 in words is "six million, eight hundred sixty-four thousand, six hundred forty".