81357733 has 16 divisors (see below), whose sum is σ = 89385984. Its totient is φ = 73716480.

The previous prime is 81357623. The next prime is 81357781. The reversal of 81357733 is 33775318.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81357733 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 81357692 and 81357701.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81357433) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 166816 + ... + 167302.

It is an arithmetic number, because the mean of its divisors is an integer number (5586624).

Almost surely, 2^81357733 is an apocalyptic number.

It is an amenable number.

81357733 is a deficient number, since it is larger than the sum of its proper divisors (8028251).

81357733 is a wasteful number, since it uses less digits than its factorization.

81357733 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 852.

The product of its digits is 52920, while the sum is 37.

The square root of 81357733 is about 9019.8521606510. The cubic root of 81357733 is about 433.3108989700.

The spelling of 81357733 in words is "eighty-one million, three hundred fifty-seven thousand, seven hundred thirty-three".