64839760 has 80 divisors (see below), whose sum is σ = 159096960. Its totient is φ = 24527360.

The previous prime is 64839721. The next prime is 64839769. The reversal of 64839760 is 6793846.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (80).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64839769) 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, 240906 + ... + 241174.

It is an arithmetic number, because the mean of its divisors is an integer number (1988712).

Almost surely, 2^64839760 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 64839760, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (79548480).

64839760 is an abundant number, since it is smaller than the sum of its proper divisors (94257200).

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

64839760 is a wasteful number, since it uses less digits than its factorization.

64839760 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 436 (or 430 counting only the distinct ones).

The product of its (nonzero) digits is 217728, while the sum is 43.

The square root of 64839760 is about 8052.3139531442. The cubic root of 64839760 is about 401.7419034201.

The spelling of 64839760 in words is "sixty-four million, eight hundred thirty-nine thousand, seven hundred sixty".