81273021301 has 4 divisors (see below), whose sum is σ = 81992251692. Its totient is φ = 80553790912.

The previous prime is 81273021299. The next prime is 81273021317. The reversal of 81273021301 is 10312037218.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 19682687025 + 61590334276 = 140295^2 + 248174^2 .

It is a cyclic number.

It is not a de Polignac number, because 81273021301 - 2¹ = 81273021299 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 81273021301.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81273021701) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 359615026 + ... + 359615251.

It is an arithmetic number, because the mean of its divisors is an integer number (20498062923).

Almost surely, 2^81273021301 is an apocalyptic number.

It is an amenable number.

81273021301 is a deficient number, since it is larger than the sum of its proper divisors (719230391).

81273021301 is a wasteful number, since it uses less digits than its factorization.

81273021301 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 719230390.

The product of its (nonzero) digits is 2016, while the sum is 28.

Adding to 81273021301 its reverse (10312037218), we get a palindrome (91585058519).

The spelling of 81273021301 in words is "eighty-one billion, two hundred seventy-three million, twenty-one thousand, three hundred one".