64642744320 has 864 divisors, whose sum is σ = 266807048256. Its totient is φ = 13212057600.

The previous prime is 64642744303. The next prime is 64642744337. The reversal of 64642744320 is 2344724646.

It is an interprime number because it is at equal distance from previous prime (64642744303) and next prime (64642744337).

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1059717090 + ... + 1059717150.

It is an arithmetic number, because the mean of its divisors is an integer number (308804454).

Almost surely, 2^64642744320 is an apocalyptic number.

64642744320 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 64642744320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (133403524128).

64642744320 is an abundant number, since it is smaller than the sum of its proper divisors (202164303936).

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

64642744320 is an equidigital number, since it uses as much as digits as its factorization.

64642744320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 128 (or 89 counting only the distinct ones).

The product of its (nonzero) digits is 774144, while the sum is 42.

The spelling of 64642744320 in words is "sixty-four billion, six hundred forty-two million, seven hundred forty-four thousand, three hundred twenty".