64304640 has 120 divisors (see below), whose sum is σ = 222784848. Its totient is φ = 17141760.

The previous prime is 64304621. The next prime is 64304663. The reversal of 64304640 is 4640346.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (120).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 21645 + ... + 24435.

Almost surely, 2^64304640 is an apocalyptic number.

64304640 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 64304640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (111392424).

64304640 is an abundant number, since it is smaller than the sum of its proper divisors (158480208).

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

64304640 is a wasteful number, since it uses less digits than its factorization.

64304640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2820 (or 2801 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 27.

The square root of 64304640 is about 8019.0173961652. The cubic root of 64304640 is about 400.6336623168.

Adding to 64304640 its reverse (4640346), we get a palindrome (68944986).

It can be divided in two parts, 64 and 304640, that added together give a square (304704 = 552²).

The spelling of 64304640 in words is "sixty-four million, three hundred four thousand, six hundred forty".