81885020 has 48 divisors (see below), whose sum is σ = 197588160. Its totient is φ = 27922944.

The previous prime is 81885019. The next prime is 81885059. The reversal of 81885020 is 2058818.

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, 26096 + ... + 29064.

It is an arithmetic number, because the mean of its divisors is an integer number (4116420).

Almost surely, 2^81885020 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 81885020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (98794080).

81885020 is an abundant number, since it is smaller than the sum of its proper divisors (115703140).

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

81885020 is a wasteful number, since it uses less digits than its factorization.

81885020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3182 (or 3180 counting only the distinct ones).

The product of its (nonzero) digits is 5120, while the sum is 32.

The square root of 81885020 is about 9049.0342026097. The cubic root of 81885020 is about 434.2449932346.

The spelling of 81885020 in words is "eighty-one million, eight hundred eighty-five thousand, twenty".