81305649833 has 8 divisors (see below), whose sum is σ = 81366380928. Its totient is φ = 81244947184.

The previous prime is 81305649797. The next prime is 81305649847. The reversal of 81305649833 is 33894650318.

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 81305649833 - 2⁸ = 81305649577 is a prime.

It is a super-2 number, since 2×81305649833² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81305649883) 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, 10518416 + ... + 10526142.

It is an arithmetic number, because the mean of its divisors is an integer number (10170797616).

Almost surely, 2^81305649833 is an apocalyptic number.

It is an amenable number.

81305649833 is a deficient number, since it is larger than the sum of its proper divisors (60731095).

81305649833 is a wasteful number, since it uses less digits than its factorization.

81305649833 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14223.

The product of its (nonzero) digits is 1866240, while the sum is 50.

The spelling of 81305649833 in words is "eighty-one billion, three hundred five million, six hundred forty-nine thousand, eight hundred thirty-three".