81530273 has 8 divisors (see below), whose sum is σ = 93623520. Its totient is φ = 70217280.

The previous prime is 81530243. The next prime is 81530287. The reversal of 81530273 is 37203518.

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 81530273 - 2¹² = 81526177 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81530213) 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, 194840 + ... + 195257.

It is an arithmetic number, because the mean of its divisors is an integer number (11702940).

Almost surely, 2^81530273 is an apocalyptic number.

It is an amenable number.

81530273 is a deficient number, since it is larger than the sum of its proper divisors (12093247).

81530273 is a wasteful number, since it uses less digits than its factorization.

81530273 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 390127.

The product of its (nonzero) digits is 5040, while the sum is 29.

The square root of 81530273 is about 9029.4115533627. The cubic root of 81530273 is about 433.6169984241.

The spelling of 81530273 in words is "eighty-one million, five hundred thirty thousand, two hundred seventy-three".