81884780 has 12 divisors (see below), whose sum is σ = 171958080. Its totient is φ = 32753904.

The previous prime is 81884741. The next prime is 81884809. The reversal of 81884780 is 8748818.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2047100 + ... + 2047139.

It is an arithmetic number, because the mean of its divisors is an integer number (14329840).

Almost surely, 2^81884780 is an apocalyptic number.

It is an amenable number.

81884780 is an abundant number, since it is smaller than the sum of its proper divisors (90073300).

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

81884780 is a wasteful number, since it uses less digits than its factorization.

81884780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4094248 (or 4094246 counting only the distinct ones).

The product of its (nonzero) digits is 114688, while the sum is 44.

The square root of 81884780 is about 9049.0209415163. The cubic root of 81884780 is about 434.2445689856.

The spelling of 81884780 in words is "eighty-one million, eight hundred eighty-four thousand, seven hundred eighty".