81880928 has 12 divisors (see below), whose sum is σ = 161203140. Its totient is φ = 40940448.

The previous prime is 81880921. The next prime is 81880933. The reversal of 81880928 is 82908818.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81880921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1279358 + ... + 1279421.

It is an arithmetic number, because the mean of its divisors is an integer number (13433595).

Almost surely, 2^81880928 is an apocalyptic number.

It is an amenable number.

81880928 is a deficient number, since it is larger than the sum of its proper divisors (79322212).

81880928 is a wasteful number, since it uses less digits than its factorization.

81880928 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2558789 (or 2558781 counting only the distinct ones).

The product of its (nonzero) digits is 73728, while the sum is 44.

The square root of 81880928 is about 9048.8080983078. The cubic root of 81880928 is about 434.2377596766.

The spelling of 81880928 in words is "eighty-one million, eight hundred eighty thousand, nine hundred twenty-eight".