64439123865 has 32 divisors (see below), whose sum is σ = 112030003200. Its totient is φ = 31508429760.

The previous prime is 64439123857. The next prime is 64439123867. The reversal of 64439123865 is 56832193446.

It is not a de Polignac number, because 64439123865 - 2³ = 64439123857 is a prime.

It is not an unprimeable number, because it can be changed into a prime (64439123867) 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, 3637975 + ... + 3655644.

It is an arithmetic number, because the mean of its divisors is an integer number (3500937600).

Almost surely, 2^64439123865 is an apocalyptic number.

It is an amenable number.

64439123865 is a deficient number, since it is larger than the sum of its proper divisors (47590879335).

64439123865 is a wasteful number, since it uses less digits than its factorization.

64439123865 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7293677.

The product of its digits is 3732480, while the sum is 51.

The spelling of 64439123865 in words is "sixty-four billion, four hundred thirty-nine million, one hundred twenty-three thousand, eight hundred sixty-five".