64383991 has 6 divisors (see below), whose sum is σ = 74895720. Its totient is φ = 55186236.

The previous prime is 64383967. The next prime is 64384009. The reversal of 64383991 is 19938346.

It is not a de Polignac number, because 64383991 - 2⁹ = 64383479 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64383901) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 656931 + ... + 657028.

It is an arithmetic number, because the mean of its divisors is an integer number (12482620).

Almost surely, 2^64383991 is an apocalyptic number.

64383991 is a deficient number, since it is larger than the sum of its proper divisors (10511729).

64383991 is a wasteful number, since it uses less digits than its factorization.

64383991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1313973 (or 1313966 counting only the distinct ones).

The product of its digits is 139968, while the sum is 43.

The square root of 64383991 is about 8023.9635467766. The cubic root of 64383991 is about 400.7983866367.

The spelling of 64383991 in words is "sixty-four million, three hundred eighty-three thousand, nine hundred ninety-one".