81665301 has 8 divisors (see below), whose sum is σ = 109944640. Its totient is φ = 53914752.

The previous prime is 81665291. The next prime is 81665303. The reversal of 81665301 is 10356618.

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

It is not a de Polignac number, because 81665301 - 2¹⁹ = 81141013 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 (81665303) 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, 131836 + ... + 132453.

It is an arithmetic number, because the mean of its divisors is an integer number (13743080).

Almost surely, 2^81665301 is an apocalyptic number.

It is an amenable number.

81665301 is a deficient number, since it is larger than the sum of its proper divisors (28279339).

81665301 is a wasteful number, since it uses less digits than its factorization.

81665301 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 264395.

The product of its (nonzero) digits is 4320, while the sum is 30.

The square root of 81665301 is about 9036.8855807739. The cubic root of 81665301 is about 433.8562475621.

The spelling of 81665301 in words is "eighty-one million, six hundred sixty-five thousand, three hundred one".