81198733 has 16 divisors (see below), whose sum is σ = 103305600. Its totient is φ = 63268800.

The previous prime is 81198731. The next prime is 81198779. The reversal of 81198733 is 33789118.

It is not a de Polignac number, because 81198733 - 2¹ = 81198731 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 (81198731) 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 15 ways as a sum of consecutive naturals, for example, 6988 + ... + 14533.

It is an arithmetic number, because the mean of its divisors is an integer number (6456600).

Almost surely, 2^81198733 is an apocalyptic number.

It is an amenable number.

81198733 is a deficient number, since it is larger than the sum of its proper divisors (22106867).

81198733 is a wasteful number, since it uses less digits than its factorization.

81198733 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21553 (or 21539 counting only the distinct ones).

The product of its digits is 36288, while the sum is 40.

The square root of 81198733 is about 9011.0339584312. The cubic root of 81198733 is about 433.0284371341.

The spelling of 81198733 in words is "eighty-one million, one hundred ninety-eight thousand, seven hundred thirty-three".