81045588 has 24 divisors (see below), whose sum is σ = 203653408. Its totient is φ = 24937056.

The previous prime is 81045581. The next prime is 81045589. The reversal of 81045588 is 88554018.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81045581) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 259606 + ... + 259917.

Almost surely, 2^81045588 is an apocalyptic number.

It is an amenable number.

81045588 is an abundant number, since it is smaller than the sum of its proper divisors (122607820).

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

81045588 is a wasteful number, since it uses less digits than its factorization.

81045588 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 519543 (or 519541 counting only the distinct ones).

The product of its (nonzero) digits is 51200, while the sum is 39.

The square root of 81045588 is about 9002.5323104113. The cubic root of 81045588 is about 432.7560278112.

The spelling of 81045588 in words is "eighty-one million, forty-five thousand, five hundred eighty-eight".