81885380 has 12 divisors (see below), whose sum is σ = 171959340. Its totient is φ = 32754144.

The previous prime is 81885347. The next prime is 81885389. The reversal of 81885380 is 8358818.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 53348416 + 28536964 = 7304^2 + 5342^2 .

It is a hoax number, since the sum of its digits (41) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (81885389) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2047115 + ... + 2047154.

It is an arithmetic number, because the mean of its divisors is an integer number (14329945).

Almost surely, 2^81885380 is an apocalyptic number.

It is an amenable number.

81885380 is an abundant number, since it is smaller than the sum of its proper divisors (90073960).

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

81885380 is a wasteful number, since it uses less digits than its factorization.

81885380 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4094278 (or 4094276 counting only the distinct ones).

The product of its (nonzero) digits is 61440, while the sum is 41.

The square root of 81885380 is about 9049.0540942134. The cubic root of 81885380 is about 434.2456296064.

The spelling of 81885380 in words is "eighty-one million, eight hundred eighty-five thousand, three hundred eighty".