64320640 has 32 divisors (see below), whose sum is σ = 153768060. Its totient is φ = 25728000.

The previous prime is 64320631. The next prime is 64320653. The reversal of 64320640 is 4602346.

It can be written as a sum of positive squares in 2 ways, for example, as 60093504 + 4227136 = 7752^2 + 2056^2 .

It is a tau number, because it is divible by the number of its divisors (32).

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 49611 + ... + 50890.

Almost surely, 2^64320640 is an apocalyptic number.

It is an amenable number.

64320640 is an abundant number, since it is smaller than the sum of its proper divisors (89447420).

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

64320640 is a wasteful number, since it uses less digits than its factorization.

64320640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 100520 (or 100508 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 25.

The square root of 64320640 is about 8020.0149625796. The cubic root of 64320640 is about 400.6668875346. Note that the first 3 decimals are identical.

Adding to 64320640 its reverse (4602346), we get a palindrome (68922986).

The spelling of 64320640 in words is "sixty-four million, three hundred twenty thousand, six hundred forty".