81304528 has 20 divisors (see below), whose sum is σ = 157682368. Its totient is φ = 40612320.

The previous prime is 81304507. The next prime is 81304541. The reversal of 81304528 is 82540318.

It is a super-2 number, since 2×81304528² = 13220852546605568, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 81304528.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20983 + ... + 24553.

Almost surely, 2^81304528 is an apocalyptic number.

It is an amenable number.

81304528 is a deficient number, since it is larger than the sum of its proper divisors (76377840).

81304528 is a wasteful number, since it uses less digits than its factorization.

81304528 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5002 (or 4996 counting only the distinct ones).

The product of its (nonzero) digits is 7680, while the sum is 31.

The square root of 81304528 is about 9016.9023505858. The cubic root of 81304528 is about 433.2164218465.

The spelling of 81304528 in words is "eighty-one million, three hundred four thousand, five hundred twenty-eight".