64639998192 has 640 divisors, whose sum is σ = 236236308480. Its totient is φ = 14712192000.

The previous prime is 64639998191. The next prime is 64639998209. The reversal of 64639998192 is 29189993646.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (66).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64639998191) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 50069067 + ... + 50070357.

It is an arithmetic number, because the mean of its divisors is an integer number (369119232).

Almost surely, 2^64639998192 is an apocalyptic number.

64639998192 is a gapful number since it is divisible by the number (62) 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 64639998192, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (118118154240).

64639998192 is an abundant number, since it is smaller than the sum of its proper divisors (171596310288).

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

64639998192 is a wasteful number, since it uses less digits than its factorization.

64639998192 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1393 (or 1387 counting only the distinct ones).

The product of its digits is 45349632, while the sum is 66.

The spelling of 64639998192 in words is "sixty-four billion, six hundred thirty-nine million, nine hundred ninety-eight thousand, one hundred ninety-two".