64687672728 has 192 divisors, whose sum is σ = 203279032320. Its totient is φ = 18202060800.

The previous prime is 64687672727. The next prime is 64687672729. The reversal of 64687672728 is 82727678646.

It is an interprime number because it is at equal distance from previous prime (64687672727) and next prime (64687672729).

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64687672727) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 10312233 + ... + 10318503.

It is an arithmetic number, because the mean of its divisors is an integer number (1058744960).

Almost surely, 2^64687672728 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 64687672728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (101639516160).

64687672728 is an abundant number, since it is smaller than the sum of its proper divisors (138591359592).

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

64687672728 is a wasteful number, since it uses less digits than its factorization.

64687672728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6598 (or 6591 counting only the distinct ones).

The product of its digits is 75866112, while the sum is 63.

The spelling of 64687672728 in words is "sixty-four billion, six hundred eighty-seven million, six hundred seventy-two thousand, seven hundred twenty-eight".