6557440 has 72 divisors (see below), whose sum is σ = 16188480. Its totient is φ = 2543616.

The previous prime is 6557429. The next prime is 6557459. The reversal of 6557440 is 447556.

It is a happy number.

It is an Ulam number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 60106 + ... + 60214.

It is an arithmetic number, because the mean of its divisors is an integer number (224840).

Almost surely, 2^6557440 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 6557440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (8094240).

6557440 is an abundant number, since it is smaller than the sum of its proper divisors (9631040).

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

6557440 is a wasteful number, since it uses less digits than its factorization.

6557440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 177 (or 163 counting only the distinct ones).

The product of its (nonzero) digits is 16800, while the sum is 31.

The square root of 6557440 is about 2560.7498901689. The cubic root of 6557440 is about 187.1736783310.

The spelling of 6557440 in words is "six million, five hundred fifty-seven thousand, four hundred forty".