6428979840 has 512 divisors, whose sum is σ = 22913280000. Its totient is φ = 1526611968.

The previous prime is 6428979829. The next prime is 6428979847. The reversal of 6428979840 is 489798246.

It is a Harshad number since it is a multiple of its sum of digits (57).

It is not an unprimeable number, because it can be changed into a prime (6428979847) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 62417229 + ... + 62417331.

It is an arithmetic number, because the mean of its divisors is an integer number (44752500).

Almost surely, 2^6428979840 is an apocalyptic number.

6428979840 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 6428979840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (11456640000).

6428979840 is an abundant number, since it is smaller than the sum of its proper divisors (16484300160).

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

6428979840 is a wasteful number, since it uses less digits than its factorization.

6428979840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 232 (or 220 counting only the distinct ones).

The product of its (nonzero) digits is 6967296, while the sum is 57.

The square root of 6428979840 is about 80180.9194260081. The cubic root of 6428979840 is about 1859.4336580756.

The spelling of 6428979840 in words is "six billion, four hundred twenty-eight million, nine hundred seventy-nine thousand, eight hundred forty".