81555233041 has 2 divisors, whose sum is σ = 81555233042. Its totient is φ = 81555233040.

The previous prime is 81555233017. The next prime is 81555233057. The reversal of 81555233041 is 14033255518.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 79628374225 + 1926858816 = 282185^2 + 43896^2 .

It is a cyclic number.

It is not a de Polignac number, because 81555233041 - 2³³ = 72965298449 is a prime.

It is not a weakly prime, because it can be changed into another prime (81555233741) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40777616520 + 40777616521.

It is an arithmetic number, because the mean of its divisors is an integer number (40777616521).

Almost surely, 2^81555233041 is an apocalyptic number.

It is an amenable number.

81555233041 is a deficient number, since it is larger than the sum of its proper divisors (1).

81555233041 is an equidigital number, since it uses as much as digits as its factorization.

81555233041 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 72000, while the sum is 37.

Adding to 81555233041 its reverse (14033255518), we get a palindrome (95588488559).

The spelling of 81555233041 in words is "eighty-one billion, five hundred fifty-five million, two hundred thirty-three thousand, forty-one".