64128768 has 72 divisors (see below), whose sum is σ = 186216576. Its totient is φ = 19430400.

The previous prime is 64128767. The next prime is 64128787. The reversal of 64128768 is 86782146.

It is a super-2 number, since 2×64128768² = 8224997770395648, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64128763) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4653 + ... + 12243.

Almost surely, 2^64128768 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 64128768, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (93108288).

64128768 is an abundant number, since it is smaller than the sum of its proper divisors (122087808).

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

64128768 is a wasteful number, since it uses less digits than its factorization.

64128768 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7621 (or 7607 counting only the distinct ones).

The product of its digits is 129024, while the sum is 42.

The square root of 64128768 is about 8008.0439559233. The cubic root of 64128768 is about 400.2680869500.

The spelling of 64128768 in words is "sixty-four million, one hundred twenty-eight thousand, seven hundred sixty-eight".