85661288220 has 48 divisors (see below), whose sum is σ = 241107406848. Its totient is φ = 22723410240.

The previous prime is 85661288201. The next prime is 85661288231. The reversal of 85661288220 is 2288216658.

It is a happy number.

It is a super-3 number, since 3×85661288220³ (a number of 34 digits) contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 85661288220.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3725944 + ... + 3748863.

It is an arithmetic number, because the mean of its divisors is an integer number (5023070976).

Almost surely, 2^85661288220 is an apocalyptic number.

It is an amenable number.

85661288220 is an abundant number, since it is smaller than the sum of its proper divisors (155446118628).

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

85661288220 is a wasteful number, since it uses less digits than its factorization.

85661288220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7475010 (or 7475008 counting only the distinct ones).

The product of its (nonzero) digits is 737280, while the sum is 48.

The spelling of 85661288220 in words is "eighty-five billion, six hundred sixty-one million, two hundred eighty-eight thousand, two hundred twenty".