64839720 has 64 divisors (see below), whose sum is σ = 212207040. Its totient is φ = 15718400.

The previous prime is 64839713. The next prime is 64839721. The reversal of 64839720 is 2793846.

It is not an unprimeable number, because it can be changed into a prime (64839721) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 23241 + ... + 25880.

It is an arithmetic number, because the mean of its divisors is an integer number (3315735).

Almost surely, 2^64839720 is an apocalyptic number.

64839720 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

64839720 is an abundant number, since it is smaller than the sum of its proper divisors (147367320).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

64839720 is a wasteful number, since it uses less digits than its factorization.

64839720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 49146 (or 49142 counting only the distinct ones).

The product of its (nonzero) digits is 72576, while the sum is 39.

The square root of 64839720 is about 8052.3114693857. The cubic root of 64839720 is about 401.7418208078.

The spelling of 64839720 in words is "sixty-four million, eight hundred thirty-nine thousand, seven hundred twenty".