81653 has 8 divisors (see below), whose sum is σ = 96096. Its totient is φ = 68400.

The previous prime is 81649. The next prime is 81667. The reversal of 81653 is 35618.

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 81653 - 2² = 81649 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81353) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 143 + ... + 428.

It is an arithmetic number, because the mean of its divisors is an integer number (12012).

2⁸¹⁶⁵³ is an apocalyptic number.

It is an amenable number.

81653 is a deficient number, since it is larger than the sum of its proper divisors (14443).

81653 is a wasteful number, since it uses less digits than its factorization.

81653 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 595.

The product of its digits is 720, while the sum is 23.

The square root of 81653 is about 285.7498906386. The cubic root of 81653 is about 43.3834462979.

It can be divided in two parts, 8 and 1653, that added together give a palindrome (1661).

The spelling of 81653 in words is "eighty-one thousand, six hundred fifty-three".