81809093 has 8 divisors (see below), whose sum is σ = 86246400. Its totient is φ = 77484240.

The previous prime is 81809069. The next prime is 81809149. The reversal of 81809093 is 39090818.

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 81809093 - 2¹⁴ = 81792709 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81809023) 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, 26618 + ... + 29531.

It is an arithmetic number, because the mean of its divisors is an integer number (10780800).

Almost surely, 2^81809093 is an apocalyptic number.

It is an amenable number.

81809093 is a deficient number, since it is larger than the sum of its proper divisors (4437307).

81809093 is a wasteful number, since it uses less digits than its factorization.

81809093 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56227.

The product of its (nonzero) digits is 15552, while the sum is 38.

The square root of 81809093 is about 9044.8379200514. The cubic root of 81809093 is about 434.1107354037.

The spelling of 81809093 in words is "eighty-one million, eight hundred nine thousand, ninety-three".