6466639839 has 32 divisors (see below), whose sum is σ = 9713299200. Its totient is φ = 3792821760.

The previous prime is 6466639709. The next prime is 6466639841. The reversal of 6466639839 is 9389366646.

It is a happy number.

It is not a de Polignac number, because 6466639839 - 2¹⁵ = 6466607071 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6466639859) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 133767 + ... + 175575.

It is an arithmetic number, because the mean of its divisors is an integer number (303540600).

Almost surely, 2^6466639839 is an apocalyptic number.

6466639839 is a deficient number, since it is larger than the sum of its proper divisors (3246659361).

6466639839 is a wasteful number, since it uses less digits than its factorization.

6466639839 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41975.

The product of its digits is 30233088, while the sum is 60.

The square root of 6466639839 is about 80415.4204055416. The cubic root of 6466639839 is about 1863.0573526708.

The spelling of 6466639839 in words is "six billion, four hundred sixty-six million, six hundred thirty-nine thousand, eight hundred thirty-nine".