81725888 has 14 divisors (see below), whose sum is σ = 162174936. Its totient is φ = 40862912.

The previous prime is 81725869. The next prime is 81725893. The reversal of 81725888 is 88852718.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 638420 + ... + 638547.

It is an arithmetic number, because the mean of its divisors is an integer number (11583924).

Almost surely, 2^81725888 is an apocalyptic number.

It is an amenable number.

81725888 is a deficient number, since it is larger than the sum of its proper divisors (80449048).

81725888 is a wasteful number, since it uses less digits than its factorization.

81725888 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1276979 (or 1276969 counting only the distinct ones).

The product of its digits is 286720, while the sum is 47.

The square root of 81725888 is about 9040.2371650306. The cubic root of 81725888 is about 433.9635128280.

The spelling of 81725888 in words is "eighty-one million, seven hundred twenty-five thousand, eight hundred eighty-eight".