81008653 has 12 divisors (see below), whose sum is σ = 89286624. Its totient is φ = 73497820.

The previous prime is 81008623. The next prime is 81008659. The reversal of 81008653 is 35680018.

It is not a de Polignac number, because 81008653 - 2⁹ = 81008141 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 (81008659) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 160800 + ... + 161302.

It is an arithmetic number, because the mean of its divisors is an integer number (7440552).

Almost surely, 2^81008653 is an apocalyptic number.

It is an amenable number.

81008653 is a deficient number, since it is larger than the sum of its proper divisors (8277971).

81008653 is an frugal number, since it uses more digits than its factorization.

81008653 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 558 (or 514 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 31.

The square root of 81008653 is about 9000.4807093844. The cubic root of 81008653 is about 432.6902776863.

The spelling of 81008653 in words is "eighty-one million, eight thousand, six hundred fifty-three".