6451977728 has 80 divisors (see below), whose sum is σ = 14756243040. Its totient is φ = 2760769536.

The previous prime is 6451977629. The next prime is 6451977731. The reversal of 6451977728 is 8277791546.

It is a Harshad number since it is a multiple of its sum of digits (56).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3414608 + ... + 3416496.

It is an arithmetic number, because the mean of its divisors is an integer number (184453038).

Almost surely, 2^6451977728 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 6451977728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (7378121520).

6451977728 is an abundant number, since it is smaller than the sum of its proper divisors (8304265312).

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

6451977728 is an equidigital number, since it uses as much as digits as its factorization.

6451977728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2867 (or 2851 counting only the distinct ones).

The product of its digits is 5927040, while the sum is 56.

The square root of 6451977728 is about 80324.2038740503. The cubic root of 6451977728 is about 1861.6482218270.

The spelling of 6451977728 in words is "six billion, four hundred fifty-one million, nine hundred seventy-seven thousand, seven hundred twenty-eight".