81184356061 has 2 divisors, whose sum is σ = 81184356062. Its totient is φ = 81184356060.

The previous prime is 81184356049. The next prime is 81184356067. The reversal of 81184356061 is 16065348118.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 44745363961 + 36438992100 = 211531^2 + 190890^2 .

It is a cyclic number.

It is not a de Polignac number, because 81184356061 - 2²¹ = 81182258909 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 81184355999 and 81184356017.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81184356067) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40592178030 + 40592178031.

It is an arithmetic number, because the mean of its divisors is an integer number (40592178031).

Almost surely, 2^81184356061 is an apocalyptic number.

It is an amenable number.

81184356061 is a deficient number, since it is larger than the sum of its proper divisors (1).

81184356061 is an equidigital number, since it uses as much as digits as its factorization.

81184356061 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 138240, while the sum is 43.

The spelling of 81184356061 in words is "eighty-one billion, one hundred eighty-four million, three hundred fifty-six thousand, sixty-one".