64739840 has 160 divisors (see below), whose sum is σ = 179720640. Its totient is φ = 22302720.

The previous prime is 64739839. The next prime is 64739863. The reversal of 64739840 is 4893746.

64739840 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (160).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3407351 + ... + 3407369.

It is an arithmetic number, because the mean of its divisors is an integer number (1123254).

Almost surely, 2^64739840 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 64739840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (89860320).

64739840 is an abundant number, since it is smaller than the sum of its proper divisors (114980800).

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

64739840 is an equidigital number, since it uses as much as digits as its factorization.

64739840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 75 (or 37 counting only the distinct ones).

The product of its (nonzero) digits is 145152, while the sum is 41.

The square root of 64739840 is about 8046.1071332664. The cubic root of 64739840 is about 401.5354319141.

The spelling of 64739840 in words is "sixty-four million, seven hundred thirty-nine thousand, eight hundred forty".