64333440 has 320 divisors, whose sum is σ = 246593160. Its totient is φ = 15925248.

The previous prime is 64333433. The next prime is 64333471. The reversal of 64333440 is 4433346.

It can be written as a sum of positive squares in 4 ways, for example, as 59351616 + 4981824 = 7704^2 + 2232^2 .

It is a tau number, because it is divible by the number of its divisors (320).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 881244 + ... + 881316.

Almost surely, 2^64333440 is an apocalyptic number.

64333440 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 64333440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (123296580).

64333440 is an abundant number, since it is smaller than the sum of its proper divisors (182259720).

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

64333440 is a wasteful number, since it uses less digits than its factorization.

64333440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 121 (or 100 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 27.

The square root of 64333440 is about 8020.8129263810. The cubic root of 64333440 is about 400.6934637420.

Adding to 64333440 its reverse (4433346), we get a palindrome (68766786).

The spelling of 64333440 in words is "sixty-four million, three hundred thirty-three thousand, four hundred forty".