6438635819 has 32 divisors (see below), whose sum is σ = 8250816000. Its totient is φ = 4980618720.

The previous prime is 6438635813. The next prime is 6438635873. The reversal of 6438635819 is 9185368346.

It is not a de Polignac number, because 6438635819 - 2¹⁶ = 6438570283 is a prime.

It is a super-2 number, since 2×6438635819² = 82912062419419601522, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (6438635813) 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, 518309 + ... + 530585.

It is an arithmetic number, because the mean of its divisors is an integer number (257838000).

Almost surely, 2^6438635819 is an apocalyptic number.

6438635819 is a deficient number, since it is larger than the sum of its proper divisors (1812180181).

6438635819 is a wasteful number, since it uses less digits than its factorization.

6438635819 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12448 (or 12434 counting only the distinct ones).

The product of its digits is 3732480, while the sum is 53.

The square root of 6438635819 is about 80241.1105294537. The cubic root of 6438635819 is about 1860.3641152307.

The spelling of 6438635819 in words is "six billion, four hundred thirty-eight million, six hundred thirty-five thousand, eight hundred nineteen".