6449919840 has 576 divisors, whose sum is σ = 28108394496. Its totient is φ = 1360115712.

The previous prime is 6449919829. The next prime is 6449919869. The reversal of 6449919840 is 489199446.

It is a happy number.

6449919840 is a `hidden beast` number, since 6 + 449 + 9 + 198 + 4 + 0 = 666.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 3537169 + ... + 3538991.

It is an arithmetic number, because the mean of its divisors is an integer number (48799296).

Almost surely, 2^6449919840 is an apocalyptic number.

6449919840 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 6449919840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (14054197248).

6449919840 is an abundant number, since it is smaller than the sum of its proper divisors (21658474656).

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

6449919840 is a wasteful number, since it uses less digits than its factorization.

6449919840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1873 (or 1853 counting only the distinct ones).

The product of its (nonzero) digits is 2239488, while the sum is 54.

The square root of 6449919840 is about 80311.3929651329. The cubic root of 6449919840 is about 1861.4502736897.

The spelling of 6449919840 in words is "six billion, four hundred forty-nine million, nine hundred nineteen thousand, eight hundred forty".