81773712 has 50 divisors (see below), whose sum is σ = 236680598. Its totient is φ = 27257472.

The previous prime is 81773711. The next prime is 81773719. The reversal of 81773712 is 21737718.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 43877376 + 37896336 = 6624^2 + 6156^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (81773711) 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 9 ways as a sum of consecutive naturals, for example, 30253 + ... + 32844.

Almost surely, 2^81773712 is an apocalyptic number.

It is an amenable number.

81773712 is an abundant number, since it is smaller than the sum of its proper divisors (154906886).

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

81773712 is a wasteful number, since it uses less digits than its factorization.

81773712 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63117 (or 63102 counting only the distinct ones).

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

The square root of 81773712 is about 9042.8818415370. The cubic root of 81773712 is about 434.0481446162.

It can be divided in two parts, 817 and 73712, that added together give a square (74529 = 273²).

The spelling of 81773712 in words is "eighty-one million, seven hundred seventy-three thousand, seven hundred twelve".