64553640 has 128 divisors (see below), whose sum is σ = 212889600. Its totient is φ = 15586560.

The previous prime is 64553581. The next prime is 64553647. The reversal of 64553640 is 4635546.

It is not an unprimeable number, because it can be changed into a prime (64553647) by changing a digit.

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 31 ways as a sum of consecutive naturals, for example, 51825 + ... + 53055.

It is an arithmetic number, because the mean of its divisors is an integer number (1663200).

Almost surely, 2^64553640 is an apocalyptic number.

64553640 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 64553640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (106444800).

64553640 is an abundant number, since it is smaller than the sum of its proper divisors (148335960).

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

64553640 is a wasteful number, since it uses less digits than its factorization.

64553640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1287 (or 1283 counting only the distinct ones).

The product of its (nonzero) digits is 43200, while the sum is 33.

The square root of 64553640 is about 8034.5279886251. The cubic root of 64553640 is about 401.1501066341.

It can be divided in two parts, 645 and 53640, that added together give a triangular number (54285 = T₃₂₉).

The spelling of 64553640 in words is "sixty-four million, five hundred fifty-three thousand, six hundred forty".