6451881984 has 480 divisors, whose sum is σ = 21405384000. Its totient is φ = 1926955008.

The previous prime is 6451881979. The next prime is 6451881991. The reversal of 6451881984 is 4891881546.

It is a happy number.

It is a super-2 number, since 2×6451881984² = 83253562270927552512, which contains 22 as substring.

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

It is a self number, because there is not a number n which added to its sum of digits gives 6451881984.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 72493012 + ... + 72493100.

It is an arithmetic number, because the mean of its divisors is an integer number (44594550).

Almost surely, 2^6451881984 is an apocalyptic number.

6451881984 is a gapful number since it is divisible by the number (64) 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 6451881984, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (10702692000).

6451881984 is an abundant number, since it is smaller than the sum of its proper divisors (14953502016).

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

6451881984 is a wasteful number, since it uses less digits than its factorization.

6451881984 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 165 (or 136 counting only the distinct ones).

The product of its digits is 2211840, while the sum is 54.

The square root of 6451881984 is about 80323.6078870963. The cubic root of 6451881984 is about 1861.6390131504.

The spelling of 6451881984 in words is "six billion, four hundred fifty-one million, eight hundred eighty-one thousand, nine hundred eighty-four".