85189391820 has 192 divisors, whose sum is σ = 289682480640. Its totient is φ = 20656601856.

The previous prime is 85189391809. The next prime is 85189391839. The reversal of 85189391820 is 2819398158.

85189391820 is a `hidden beast` number, since 8 + 518 + 93 + 9 + 18 + 20 = 666.

It is a super-2 number, since 2×85189391820² (a number of 23 digits) contains 22 as substring.

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 379779 + ... + 560901.

It is an arithmetic number, because the mean of its divisors is an integer number (1508762920).

Almost surely, 2^85189391820 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 85189391820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (144841240320).

85189391820 is an abundant number, since it is smaller than the sum of its proper divisors (204493088820).

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

85189391820 is a wasteful number, since it uses less digits than its factorization.

85189391820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 181221 (or 181213 counting only the distinct ones).

The product of its (nonzero) digits is 1244160, while the sum is 54.

The spelling of 85189391820 in words is "eighty-five billion, one hundred eighty-nine million, three hundred ninety-one thousand, eight hundred twenty".