85644679680 has 720 divisors, whose sum is σ = 358008228864. Its totient is φ = 18533007360.

The previous prime is 85644679663. The next prime is 85644679727. The reversal of 85644679680 is 8697644658.

85644679680 is a `hidden beast` number, since 8 + 5 + 6 + 4 + 467 + 96 + 80 = 666.

It is a tau number, because it is divible by the number of its divisors (720).

It is a super-2 number, since 2×85644679680² (a number of 23 digits) contains 22 as substring.

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

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 58221345 + ... + 58222815.

Almost surely, 2^85644679680 is an apocalyptic number.

85644679680 is a gapful number since it is divisible by the number (80) 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 85644679680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (179004114432).

85644679680 is an abundant number, since it is smaller than the sum of its proper divisors (272363549184).

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

85644679680 is a wasteful number, since it uses less digits than its factorization.

85644679680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1545 (or 1507 counting only the distinct ones).

The product of its (nonzero) digits is 69672960, while the sum is 63.

The spelling of 85644679680 in words is "eighty-five billion, six hundred forty-four million, six hundred seventy-nine thousand, six hundred eighty".