6687540 has 72 divisors (see below), whose sum is σ = 20697768. Its totient is φ = 1747200.

The previous prime is 6687539. The next prime is 6687557. The reversal of 6687540 is 457866.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 2377764 + 4309776 = 1542^2 + 2076^2 .

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

It is a junction number, because it is equal to n+sod(n) for n = 6687495 and 6687504.

It is a congruent number.

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, 9190 + ... + 9890.

It is an arithmetic number, because the mean of its divisors is an integer number (287469).

Almost surely, 2^6687540 is an apocalyptic number.

6687540 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 6687540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (10348884).

6687540 is an abundant number, since it is smaller than the sum of its proper divisors (14010228).

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

6687540 is a wasteful number, since it uses less digits than its factorization.

6687540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 769 (or 764 counting only the distinct ones).

The product of its (nonzero) digits is 40320, while the sum is 36.

The square root of 6687540 is about 2586.0278420775. The cubic root of 6687540 is about 188.4034267163.

It can be divided in two parts, 6687 and 540, that added together give a palindrome (7227).

The spelling of 6687540 in words is "six million, six hundred eighty-seven thousand, five hundred forty".