81228990041 has 2 divisors, whose sum is σ = 81228990042. Its totient is φ = 81228990040.

The previous prime is 81228989987. The next prime is 81228990061. The reversal of 81228990041 is 14009982218.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 74343475600 + 6885514441 = 272660^2 + 82979^2 .

It is a cyclic number.

It is not a de Polignac number, because 81228990041 - 2³⁴ = 64049120857 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 81228989974 and 81228990001.

It is not a weakly prime, because it can be changed into another prime (81228990061) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40614495020 + 40614495021.

It is an arithmetic number, because the mean of its divisors is an integer number (40614495021).

Almost surely, 2^81228990041 is an apocalyptic number.

It is an amenable number.

81228990041 is a deficient number, since it is larger than the sum of its proper divisors (1).

81228990041 is an equidigital number, since it uses as much as digits as its factorization.

81228990041 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 82944, while the sum is 44.

The spelling of 81228990041 in words is "eighty-one billion, two hundred twenty-eight million, nine hundred ninety thousand, forty-one".