81169733 has 4 divisors (see below), whose sum is σ = 81189888. Its totient is φ = 81149580.

The previous prime is 81169727. The next prime is 81169741. The reversal of 81169733 is 33796118.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 33796118 = 2 ⋅16898059.

It is a cyclic number.

It is not a de Polignac number, because 81169733 - 2⁴ = 81169717 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 (81169433) 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 3 ways as a sum of consecutive naturals, for example, 1733 + ... + 12858.

It is an arithmetic number, because the mean of its divisors is an integer number (20297472).

Almost surely, 2^81169733 is an apocalyptic number.

It is an amenable number.

81169733 is a deficient number, since it is larger than the sum of its proper divisors (20155).

81169733 is a wasteful number, since it uses less digits than its factorization.

81169733 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20154.

The product of its digits is 27216, while the sum is 38.

The square root of 81169733 is about 9009.4246764152. The cubic root of 81169733 is about 432.9768791869.

The spelling of 81169733 in words is "eighty-one million, one hundred sixty-nine thousand, seven hundred thirty-three".