81487660 has 24 divisors (see below), whose sum is σ = 174767040. Its totient is φ = 31901184.

The previous prime is 81487649. The next prime is 81487687. The reversal of 81487660 is 6678418.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 42405 + ... + 44284.

It is an arithmetic number, because the mean of its divisors is an integer number (7281960).

Almost surely, 2^81487660 is an apocalyptic number.

It is an amenable number.

81487660 is an abundant number, since it is smaller than the sum of its proper divisors (93279380).

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

81487660 is a wasteful number, since it uses less digits than its factorization.

81487660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 86745 (or 86743 counting only the distinct ones).

The product of its (nonzero) digits is 64512, while the sum is 40.

The square root of 81487660 is about 9027.0515673724. The cubic root of 81487660 is about 433.5414398182.

The spelling of 81487660 in words is "eighty-one million, four hundred eighty-seven thousand, six hundred sixty".