64564643808 has 540 divisors, whose sum is σ = 234774983520. Its totient is φ = 17352050688.

The previous prime is 64564643807. The next prime is 64564643809. The reversal of 64564643808 is 80834646546.

It is an interprime number because it is at equal distance from previous prime (64564643807) and next prime (64564643809).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64564643807) by changing a digit.

It is a polite number, since it can be written in 89 ways as a sum of consecutive naturals, for example, 36704433 + ... + 36706191.

It is an arithmetic number, because the mean of its divisors is an integer number (434768488).

Almost surely, 2^64564643808 is an apocalyptic number.

64564643808 is a gapful number since it is divisible by the number (68) 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 64564643808, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (117387491760).

64564643808 is an abundant number, since it is smaller than the sum of its proper divisors (170210339712).

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

64564643808 is a wasteful number, since it uses less digits than its factorization.

64564643808 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1829 (or 1788 counting only the distinct ones).

The product of its (nonzero) digits is 13271040, while the sum is 54.

The spelling of 64564643808 in words is "sixty-four billion, five hundred sixty-four million, six hundred forty-three thousand, eight hundred eight".