81228598793 has 2 divisors, whose sum is σ = 81228598794. Its totient is φ = 81228598792.

The previous prime is 81228598777. The next prime is 81228598823. The reversal of 81228598793 is 39789582218.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 76523050384 + 4705548409 = 276628^2 + 68597^2 .

It is a cyclic number.

It is not a de Polignac number, because 81228598793 - 2⁴ = 81228598777 is a prime.

It is a super-2 number, since 2×81228598793² (a number of 23 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (81228598193) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40614299396 + 40614299397.

It is an arithmetic number, because the mean of its divisors is an integer number (40614299397).

Almost surely, 2^81228598793 is an apocalyptic number.

It is an amenable number.

81228598793 is a deficient number, since it is larger than the sum of its proper divisors (1).

81228598793 is an equidigital number, since it uses as much as digits as its factorization.

81228598793 is an evil number, because the sum of its binary digits is even.

The product of its digits is 17418240, while the sum is 62.

The spelling of 81228598793 in words is "eighty-one billion, two hundred twenty-eight million, five hundred ninety-eight thousand, seven hundred ninety-three".