81660273 has 8 divisors (see below), whose sum is σ = 110665536. Its totient is φ = 53547600.

The previous prime is 81660263. The next prime is 81660283. The reversal of 81660273 is 37206618.

It is an interprime number because it is at equal distance from previous prime (81660263) and next prime (81660283).

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 81660273 - 2⁹ = 81659761 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81660223) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 222933 + ... + 223298.

It is an arithmetic number, because the mean of its divisors is an integer number (13833192).

Almost surely, 2^81660273 is an apocalyptic number.

It is an amenable number.

81660273 is a deficient number, since it is larger than the sum of its proper divisors (29005263).

81660273 is a wasteful number, since it uses less digits than its factorization.

81660273 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 446295.

The product of its (nonzero) digits is 12096, while the sum is 33.

The square root of 81660273 is about 9036.6073833049. The cubic root of 81660273 is about 433.8473434378.

The spelling of 81660273 in words is "eighty-one million, six hundred sixty thousand, two hundred seventy-three".