64388240 has 80 divisors (see below), whose sum is σ = 176655360. Its totient is φ = 21358080.

The previous prime is 64388237. The next prime is 64388257. The reversal of 64388240 is 4288346.

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

It is a Harshad number since it is a multiple of its sum of digits (35).

It is a self number, because there is not a number n which added to its sum of digits gives 64388240.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 15506 + ... + 19214.

It is an arithmetic number, because the mean of its divisors is an integer number (2208192).

Almost surely, 2^64388240 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 64388240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (88327680).

64388240 is an abundant number, since it is smaller than the sum of its proper divisors (112267120).

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

64388240 is a wasteful number, since it uses less digits than its factorization.

64388240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3760 (or 3754 counting only the distinct ones).

The product of its (nonzero) digits is 36864, while the sum is 35.

The square root of 64388240 is about 8024.2283118067. The cubic root of 64388240 is about 400.8072032947.

The spelling of 64388240 in words is "sixty-four million, three hundred eighty-eight thousand, two hundred forty".