81745829 has 8 divisors (see below), whose sum is σ = 90509088. Its totient is φ = 73204560.

The previous prime is 81745823. The next prime is 81745849. The reversal of 81745829 is 92854718.

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

It is not a de Polignac number, because 81745829 - 2¹⁶ = 81680293 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 81745829.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81745823) by changing a digit.

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, 54722 + ... + 56195.

It is an arithmetic number, because the mean of its divisors is an integer number (11313636).

Almost surely, 2^81745829 is an apocalyptic number.

It is an amenable number.

81745829 is a deficient number, since it is larger than the sum of its proper divisors (8763259).

81745829 is a wasteful number, since it uses less digits than its factorization.

81745829 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 110995.

The product of its digits is 161280, while the sum is 44.

The square root of 81745829 is about 9041.3400002433. The cubic root of 81745829 is about 433.9988054502.

Subtracting 81745829 from its reverse (92854718), we obtain a square (11108889 = 3333²).

The spelling of 81745829 in words is "eighty-one million, seven hundred forty-five thousand, eight hundred twenty-nine".