81129733 has 16 divisors (see below), whose sum is σ = 85800960. Its totient is φ = 76608000.

The previous prime is 81129731. The next prime is 81129751. The reversal of 81129733 is 33792118.

It is a cyclic number.

It is not a de Polignac number, because 81129733 - 2¹ = 81129731 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81129731) 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 15 ways as a sum of consecutive naturals, for example, 424668 + ... + 424858.

It is an arithmetic number, because the mean of its divisors is an integer number (5362560).

Almost surely, 2^81129733 is an apocalyptic number.

It is an amenable number.

81129733 is a deficient number, since it is larger than the sum of its proper divisors (4671227).

81129733 is a wasteful number, since it uses less digits than its factorization.

81129733 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 468.

The product of its digits is 9072, while the sum is 34.

The square root of 81129733 is about 9007.2045052835. The cubic root of 81129733 is about 432.9057446222.

The spelling of 81129733 in words is "eighty-one million, one hundred twenty-nine thousand, seven hundred thirty-three".