6403777920 has 256 divisors, whose sum is σ = 22972032000. Its totient is φ = 1685698560.

The previous prime is 6403777909. The next prime is 6403777927. The reversal of 6403777920 is 297773046.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6403777927) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1362775 + ... + 1367465.

It is an arithmetic number, because the mean of its divisors is an integer number (89734500).

Almost surely, 2^6403777920 is an apocalyptic number.

6403777920 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 6403777920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (11486016000).

6403777920 is an abundant number, since it is smaller than the sum of its proper divisors (16568254080).

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

6403777920 is a wasteful number, since it uses less digits than its factorization.

6403777920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4798 (or 4780 counting only the distinct ones).

The product of its (nonzero) digits is 444528, while the sum is 45.

The square root of 6403777920 is about 80023.6085164872. The cubic root of 6403777920 is about 1857.0007855702. Note that the first 3 decimals are identical.

The spelling of 6403777920 in words is "six billion, four hundred three million, seven hundred seventy-seven thousand, nine hundred twenty".