6407778 has 32 divisors (see below), whose sum is σ = 13942656. Its totient is φ = 1951488.

The previous prime is 6407773. The next prime is 6407809. The reversal of 6407778 is 8777046.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is not an unprimeable number, because it can be changed into a prime (6407773) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8451 + ... + 9177.

It is an arithmetic number, because the mean of its divisors is an integer number (435708).

Almost surely, 2^6407778 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 6407778, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (6971328).

6407778 is an abundant number, since it is smaller than the sum of its proper divisors (7534878).

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

6407778 is a wasteful number, since it uses less digits than its factorization.

6407778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 858.

The product of its (nonzero) digits is 65856, while the sum is 39.

The square root of 6407778 is about 2531.3589235824. The cubic root of 6407778 is about 185.7387359750.

The spelling of 6407778 in words is "six million, four hundred seven thousand, seven hundred seventy-eight".