6404778 has 32 divisors (see below), whose sum is σ = 14414400. Its totient is φ = 2107728.

The previous prime is 6404777. The next prime is 6404779. The reversal of 6404778 is 8774046.

It is a happy number.

6404778 is a `hidden beast` number, since 640 + 4 + 7 + 7 + 8 = 666.

It is an interprime number because it is at equal distance from previous prime (6404777) and next prime (6404779).

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (6404771) 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, 3768 + ... + 5196.

It is an arithmetic number, because the mean of its divisors is an integer number (450450).

Almost surely, 2^6404778 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 6404778, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (7207200).

6404778 is an abundant number, since it is smaller than the sum of its proper divisors (8009622).

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

6404778 is a wasteful number, since it uses less digits than its factorization.

6404778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1523 (or 1517 counting only the distinct ones).

The product of its (nonzero) digits is 37632, while the sum is 36.

The square root of 6404778 is about 2530.7662871154. The cubic root of 6404778 is about 185.7097450003.

The spelling of 6404778 in words is "six million, four hundred four thousand, seven hundred seventy-eight".