64240440 has 128 divisors (see below), whose sum is σ = 215550720. Its totient is φ = 15180800.

The previous prime is 64240417. The next prime is 64240441. The reversal of 64240440 is 4404246.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 64240440.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64240441) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 53527 + ... + 54713.

It is an arithmetic number, because the mean of its divisors is an integer number (1683990).

Almost surely, 2^64240440 is an apocalyptic number.

64240440 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 64240440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (107775360).

64240440 is an abundant number, since it is smaller than the sum of its proper divisors (151310280).

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

64240440 is a wasteful number, since it uses less digits than its factorization.

64240440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1253 (or 1249 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 24.

The square root of 64240440 is about 8015.0134123406. The cubic root of 64240440 is about 400.5002906789.

Adding to 64240440 its reverse (4404246), we get a palindrome (68644686).

The spelling of 64240440 in words is "sixty-four million, two hundred forty thousand, four hundred forty".