64989200640 has 576 divisors, whose sum is σ = 257131929600. Its totient is φ = 13622280192.

The previous prime is 64989200557. The next prime is 64989200663. The reversal of 64989200640 is 4600298946.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a self number, because there is not a number n which added to its sum of digits gives 64989200640.

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 63 ways as a sum of consecutive naturals, for example, 62549241 + ... + 62550279.

It is an arithmetic number, because the mean of its divisors is an integer number (446409600).

Almost surely, 2^64989200640 is an apocalyptic number.

64989200640 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 64989200640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (128565964800).

64989200640 is an abundant number, since it is smaller than the sum of its proper divisors (192142728960).

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

64989200640 is a wasteful number, since it uses less digits than its factorization.

64989200640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1262 (or 1248 counting only the distinct ones).

The product of its (nonzero) digits is 746496, while the sum is 48.

The spelling of 64989200640 in words is "sixty-four billion, nine hundred eighty-nine million, two hundred thousand, six hundred forty".