64217440 has 72 divisors (see below), whose sum is σ = 176504832. Its totient is φ = 22014720.

The previous prime is 64217437. The next prime is 64217453. The reversal of 64217440 is 4471246.

64217440 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is a junction number, because it is equal to n+sod(n) for n = 64217399 and 64217408.

It is a congruent number.

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 11 ways as a sum of consecutive naturals, for example, 3745 + ... + 11935.

It is an arithmetic number, because the mean of its divisors is an integer number (2451456).

Almost surely, 2^64217440 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 64217440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (88252416).

64217440 is an abundant number, since it is smaller than the sum of its proper divisors (112287392).

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

64217440 is a wasteful number, since it uses less digits than its factorization.

64217440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8220 (or 8205 counting only the distinct ones).

The product of its (nonzero) digits is 5376, while the sum is 28.

The square root of 64217440 is about 8013.5784765609. The cubic root of 64217440 is about 400.4524879436.

Adding to 64217440 its reverse (4471246), we get a palindrome (68688686).

It can be divided in two parts, 6421 and 7440, that added together give a triangular number (13861 = T₁₆₆).

The spelling of 64217440 in words is "sixty-four million, two hundred seventeen thousand, four hundred forty".