6428989440 has 480 divisors, whose sum is σ = 24116732640. Its totient is φ = 1634992128.

The previous prime is 6428989421. The next prime is 6428989447. The reversal of 6428989440 is 449898246.

6428989440 is a `hidden beast` number, since 6 + 42 + 89 + 89 + 440 = 666.

It is a tau number, because it is divible by the number of its divisors (480).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6428989447) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 19076952 + ... + 19077288.

It is an arithmetic number, because the mean of its divisors is an integer number (50243193).

Almost surely, 2^6428989440 is an apocalyptic number.

6428989440 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 6428989440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (12058366320).

6428989440 is an abundant number, since it is smaller than the sum of its proper divisors (17687743200).

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

6428989440 is a wasteful number, since it uses less digits than its factorization.

6428989440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 399 (or 370 counting only the distinct ones).

The product of its (nonzero) digits is 3981312, while the sum is 54.

The square root of 6428989440 is about 80180.9792906023. The cubic root of 6428989440 is about 1859.4345836011.

The spelling of 6428989440 in words is "six billion, four hundred twenty-eight million, nine hundred eighty-nine thousand, four hundred forty".