85121777664 has 1200 divisors, whose sum is σ = 342559324800. Its totient is φ = 20808990720.

The previous prime is 85121777641. The next prime is 85121777669. The reversal of 85121777664 is 46677712158.

It is a Harshad number since it is a multiple of its sum of digits (54).

Its product of digits (3951360) is a multiple of the sum of its prime divisors (40).

It is a self number, because there is not a number n which added to its sum of digits gives 85121777664.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (85121777669) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 5007163384 + ... + 5007163400.

It is an arithmetic number, because the mean of its divisors is an integer number (285466104).

Almost surely, 2^85121777664 is an apocalyptic number.

85121777664 is a gapful number since it is divisible by the number (84) 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 85121777664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (171279662400).

85121777664 is an abundant number, since it is smaller than the sum of its proper divisors (257437547136).

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

85121777664 is an equidigital number, since it uses as much as digits as its factorization.

85121777664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 89 (or 40 counting only the distinct ones).

The product of its digits is 3951360, while the sum is 54.

The spelling of 85121777664 in words is "eighty-five billion, one hundred twenty-one million, seven hundred seventy-seven thousand, six hundred sixty-four".