64440320 has 192 divisors, whose sum is σ = 188697600. Its totient is φ = 20643840.

The previous prime is 64440293. The next prime is 64440373. The reversal of 64440320 is 2304446.

It is a happy number.

It is a congruent number.

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, 2078705 + ... + 2078735.

It is an arithmetic number, because the mean of its divisors is an integer number (982800).

Almost surely, 2^64440320 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 64440320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (94348800).

64440320 is an abundant number, since it is smaller than the sum of its proper divisors (124257280).

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

64440320 is a wasteful number, since it uses less digits than its factorization.

64440320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 94 (or 74 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 23.

The square root of 64440320 is about 8027.4728277335. The cubic root of 64440320 is about 400.9152375865.

Adding to 64440320 its reverse (2304446), we get a palindrome (66744766).

The spelling of 64440320 in words is "sixty-four million, four hundred forty thousand, three hundred twenty".