64685219256 has 192 divisors, whose sum is σ = 217553356800. Its totient is φ = 16943904000.

The previous prime is 64685219243. The next prime is 64685219257. The reversal of 64685219256 is 65291258646.

64685219256 is a `hidden beast` number, since 6 + 4 + 68 + 521 + 9 + 2 + 56 = 666.

It is a super-3 number, since 3×64685219256³ (a number of 33 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64685219257) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 187906 + ... + 405806.

It is an arithmetic number, because the mean of its divisors is an integer number (1133090400).

Almost surely, 2^64685219256 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 64685219256, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (108776678400).

64685219256 is an abundant number, since it is smaller than the sum of its proper divisors (152868137544).

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

64685219256 is a wasteful number, since it uses less digits than its factorization.

64685219256 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 217970 (or 217963 counting only the distinct ones).

The product of its digits is 6220800, while the sum is 54.

The spelling of 64685219256 in words is "sixty-four billion, six hundred eighty-five million, two hundred nineteen thousand, two hundred fifty-six".