81748723 has 8 divisors (see below), whose sum is σ = 94959200. Its totient is φ = 68921280.

The previous prime is 81748721. The next prime is 81748727. The reversal of 81748723 is 32784718.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 81748723 - 2¹ = 81748721 is a prime.

It is the 9042-nd Hogben number.

It is not an unprimeable number, because it can be changed into a prime (81748721) by changing a digit.

It is a nontrivial repunit in base 9041.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 95298 + ... + 96151.

It is an arithmetic number, because the mean of its divisors is an integer number (11869900).

Almost surely, 2^81748723 is an apocalyptic number.

81748723 is a deficient number, since it is larger than the sum of its proper divisors (13210477).

81748723 is a wasteful number, since it uses less digits than its factorization.

81748723 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 191517.

The product of its digits is 75264, while the sum is 40.

The square root of 81748723 is about 9041.5000414754. The cubic root of 81748723 is about 434.0039269255.

The spelling of 81748723 in words is "eighty-one million, seven hundred forty-eight thousand, seven hundred twenty-three".