81182118133 has 2 divisors, whose sum is σ = 81182118134. Its totient is φ = 81182118132.

The previous prime is 81182118119. The next prime is 81182118139. The reversal of 81182118133 is 33181128118.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 62897128849 + 18284989284 = 250793^2 + 135222^2 .

It is a cyclic number.

It is not a de Polignac number, because 81182118133 - 2¹³ = 81182109941 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 81182118092 and 81182118101.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81182118139) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40591059066 + 40591059067.

It is an arithmetic number, because the mean of its divisors is an integer number (40591059067).

Almost surely, 2^81182118133 is an apocalyptic number.

It is an amenable number.

81182118133 is a deficient number, since it is larger than the sum of its proper divisors (1).

81182118133 is an equidigital number, since it uses as much as digits as its factorization.

81182118133 is an evil number, because the sum of its binary digits is even.

The product of its digits is 9216, while the sum is 37.

The spelling of 81182118133 in words is "eighty-one billion, one hundred eighty-two million, one hundred eighteen thousand, one hundred thirty-three".