6556440 has 64 divisors (see below), whose sum is σ = 21461760. Its totient is φ = 1589120.

The previous prime is 6556439. The next prime is 6556483. The reversal of 6556440 is 446556.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 6556398 and 6556407.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1164 + ... + 3803.

It is an arithmetic number, because the mean of its divisors is an integer number (335340).

Almost surely, 2^6556440 is an apocalyptic number.

6556440 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

6556440 is an abundant number, since it is smaller than the sum of its proper divisors (14905320).

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

6556440 is a wasteful number, since it uses less digits than its factorization.

6556440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4992 (or 4988 counting only the distinct ones).

The product of its (nonzero) digits is 14400, while the sum is 30.

The square root of 6556440 is about 2560.5546274196. The cubic root of 6556440 is about 187.1641632766.

It can be divided in two parts, 6556 and 440, that added together give a palindrome (6996).

The spelling of 6556440 in words is "six million, five hundred fifty-six thousand, four hundred forty".