81335651 has 8 divisors (see below), whose sum is σ = 82635504. Its totient is φ = 80040960.

The previous prime is 81335629. The next prime is 81335669. The reversal of 81335651 is 15653318.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 81335651 - 2¹⁴ = 81319267 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81335671) 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 7 ways as a sum of consecutive naturals, for example, 41156 + ... + 43086.

It is an arithmetic number, because the mean of its divisors is an integer number (10329438).

Almost surely, 2^81335651 is an apocalyptic number.

81335651 is a deficient number, since it is larger than the sum of its proper divisors (1299853).

81335651 is a wasteful number, since it uses less digits than its factorization.

81335651 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2581.

The product of its digits is 10800, while the sum is 32.

The square root of 81335651 is about 9018.6279998678. The cubic root of 81335651 is about 433.2716925471.

Adding to 81335651 its reverse (15653318), we get a palindrome (96988969).

The spelling of 81335651 in words is "eighty-one million, three hundred thirty-five thousand, six hundred fifty-one".