81588772 has 12 divisors (see below), whose sum is σ = 144167296. Its totient is φ = 40398120.

The previous prime is 81588769. The next prime is 81588779. The reversal of 81588772 is 27788518.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (81588779) by changing a digit.

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, 98604 + ... + 99427.

Almost surely, 2^81588772 is an apocalyptic number.

It is an amenable number.

81588772 is a deficient number, since it is larger than the sum of its proper divisors (62578524).

81588772 is a wasteful number, since it uses less digits than its factorization.

81588772 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 198138 (or 198136 counting only the distinct ones).

The product of its digits is 250880, while the sum is 46.

The square root of 81588772 is about 9032.6503308830. The cubic root of 81588772 is about 433.7206821865.

The spelling of 81588772 in words is "eighty-one million, five hundred eighty-eight thousand, seven hundred seventy-two".