81488728 has 8 divisors (see below), whose sum is σ = 152791380. Its totient is φ = 40744360.

The previous prime is 81488713. The next prime is 81488731. The reversal of 81488728 is 82788418.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (8).

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, 5093038 + ... + 5093053.

Almost surely, 2^81488728 is an apocalyptic number.

It is an amenable number.

81488728 is a deficient number, since it is larger than the sum of its proper divisors (71302652).

81488728 is a wasteful number, since it uses less digits than its factorization.

81488728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10186097 (or 10186093 counting only the distinct ones).

The product of its digits is 229376, while the sum is 46.

The square root of 81488728 is about 9027.1107227064. The cubic root of 81488728 is about 433.5433338483.

The spelling of 81488728 in words is "eighty-one million, four hundred eighty-eight thousand, seven hundred twenty-eight".