85172199840 has 1728 divisors, whose sum is σ = 399666234240. Its totient is φ = 16930529280.

The previous prime is 85172199811. The next prime is 85172199869. The reversal of 85172199840 is 4899127158.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (85172199811) and next prime (85172199869).

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

It is an unprimeable number.

It is a polite number, since it can be written in 287 ways as a sum of consecutive naturals, for example, 470564550 + ... + 470564730.

It is an arithmetic number, because the mean of its divisors is an integer number (231288330).

Almost surely, 2^85172199840 is an apocalyptic number.

85172199840 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 85172199840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (199833117120).

85172199840 is an abundant number, since it is smaller than the sum of its proper divisors (314494034400).

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

85172199840 is a wasteful number, since it uses less digits than its factorization.

85172199840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 257 (or 230 counting only the distinct ones).

The product of its (nonzero) digits is 1451520, while the sum is 54.

The spelling of 85172199840 in words is "eighty-five billion, one hundred seventy-two million, one hundred ninety-nine thousand, eight hundred forty".