6581778 has 48 divisors (see below), whose sum is σ = 15606144. Its totient is φ = 1844640.

The previous prime is 6581767. The next prime is 6581779. The reversal of 6581778 is 8771856.

It is a Smith number, since the sum of its digits (42) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is not an unprimeable number, because it can be changed into a prime (6581779) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 17751 + ... + 18117.

It is an arithmetic number, because the mean of its divisors is an integer number (325128).

Almost surely, 2^6581778 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 6581778, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (7803072).

6581778 is an abundant number, since it is smaller than the sum of its proper divisors (9024366).

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

6581778 is a wasteful number, since it uses less digits than its factorization.

6581778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 447 (or 440 counting only the distinct ones).

The product of its digits is 94080, while the sum is 42.

The square root of 6581778 is about 2565.4976125500. The cubic root of 6581778 is about 187.4049580545.

The spelling of 6581778 in words is "six million, five hundred eighty-one thousand, seven hundred seventy-eight".