6447999605 has 6 divisors (see below), whose sum is σ = 7737814998. Its totient is φ = 5158256040.

The previous prime is 6447999589. The next prime is 6447999641. The reversal of 6447999605 is 5069997446.

It can be written as a sum of positive squares in only one way, i.e., 5158399684 + 1289599921 = 71822^2 + 35911^2 .

It is not a de Polignac number, because 6447999605 - 2⁴ = 6447999589 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 161600 + ... + 197510.

It is an arithmetic number, because the mean of its divisors is an integer number (1289635833).

Almost surely, 2^6447999605 is an apocalyptic number.

It is an amenable number.

6447999605 is a deficient number, since it is larger than the sum of its proper divisors (1289815393).

6447999605 is an frugal number, since it uses more digits than its factorization.

6447999605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71827 (or 35916 counting only the distinct ones).

The product of its (nonzero) digits is 14696640, while the sum is 59.

The square root of 6447999605 is about 80299.4371399949. The cubic root of 6447999605 is about 1861.2655284095.

The spelling of 6447999605 in words is "six billion, four hundred forty-seven million, nine hundred ninety-nine thousand, six hundred five".