81369733 has 4 divisors (see below), whose sum is σ = 81991008. Its totient is φ = 80748460.

The previous prime is 81369709. The next prime is 81369749. The reversal of 81369733 is 33796318.

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.

It is a cyclic number.

It is not a de Polignac number, because 81369733 - 2⁹ = 81369221 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 (81369703) 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, 310441 + ... + 310702.

It is an arithmetic number, because the mean of its divisors is an integer number (20497752).

Almost surely, 2^81369733 is an apocalyptic number.

It is an amenable number.

81369733 is a deficient number, since it is larger than the sum of its proper divisors (621275).

81369733 is a wasteful number, since it uses less digits than its factorization.

81369733 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 621274.

The product of its digits is 81648, while the sum is 40.

The square root of 81369733 is about 9020.5173354969. The cubic root of 81369733 is about 433.3322019037.

The spelling of 81369733 in words is "eighty-one million, three hundred sixty-nine thousand, seven hundred thirty-three".