81273021413 has 2 divisors, whose sum is σ = 81273021414. Its totient is φ = 81273021412.

The previous prime is 81273021317. The next prime is 81273021419. The reversal of 81273021413 is 31412037218.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 81226140004 + 46881409 = 285002^2 + 6847^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81273021413 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 81273021413.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81273021419) 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 as a sum of consecutive naturals, namely, 40636510706 + 40636510707.

It is an arithmetic number, because the mean of its divisors is an integer number (40636510707).

Almost surely, 2^81273021413 is an apocalyptic number.

It is an amenable number.

81273021413 is a deficient number, since it is larger than the sum of its proper divisors (1).

81273021413 is an equidigital number, since it uses as much as digits as its factorization.

81273021413 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8064, while the sum is 32.

The spelling of 81273021413 in words is "eighty-one billion, two hundred seventy-three million, twenty-one thousand, four hundred thirteen".