6447447616 has 21 divisors (see below), whose sum is σ = 12795428689. Its totient is φ = 3223402624.

The previous prime is 6447447581. The next prime is 6447447697. The reversal of 6447447616 is 6167447446.

The square root of 6447447616 is 80296.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 2156673600 + 4290774016 = 46440^2 + 65504^2 .

It is a super-2 number, since 2×6447447616² = 83139161522128166912, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 6447447616.

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 2 ways as a sum of consecutive naturals, for example, 637350 + ... + 647386.

Almost surely, 2^6447447616 is an apocalyptic number.

6447447616 is the 80296-th square number.

It is an amenable number.

6447447616 is a deficient number, since it is larger than the sum of its proper divisors (6347981073).

6447447616 is an frugal number, since it uses more digits than its factorization.

6447447616 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20086 (or 10039 counting only the distinct ones).

The product of its digits is 2709504, while the sum is 49.

The cubic root of 6447447616 is about 1861.2124149128.

Multiplying 6447447616 by its sum of digits (49), we get a square (315924933184 = 562072²).

The spelling of 6447447616 in words is "six billion, four hundred forty-seven million, four hundred forty-seven thousand, six hundred sixteen".