81712773 has 16 divisors (see below), whose sum is σ = 121450560. Its totient is φ = 54297648.

The previous prime is 81712759. The next prime is 81712777. The reversal of 81712773 is 37721718.

It is a happy number.

It is not a de Polignac number, because 81712773 - 2²¹ = 79615621 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81712777) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3786 + ... + 13332.

It is an arithmetic number, because the mean of its divisors is an integer number (7590660).

Almost surely, 2^81712773 is an apocalyptic number.

It is an amenable number.

81712773 is a deficient number, since it is larger than the sum of its proper divisors (39737787).

81712773 is a wasteful number, since it uses less digits than its factorization.

81712773 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9873 (or 9867 counting only the distinct ones).

The product of its digits is 16464, while the sum is 36.

The square root of 81712773 is about 9039.5117677892. The cubic root of 81712773 is about 433.9402980871.

The spelling of 81712773 in words is "eighty-one million, seven hundred twelve thousand, seven hundred seventy-three".