11867821081 has 2 divisors, whose sum is σ = 11867821082. Its totient is φ = 11867821080.

The previous prime is 11867821033. The next prime is 11867821127. The reversal of 11867821081 is 18012876811.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10576065600 + 1291755481 = 102840^2 + 35941^2 .

It is a cyclic number.

It is not a de Polignac number, because 11867821081 - 2⁷ = 11867820953 is a prime.

It is a super-2 number, since 2×11867821081² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (11867828081) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5933910540 + 5933910541.

It is an arithmetic number, because the mean of its divisors is an integer number (5933910541).

Almost surely, 2^11867821081 is an apocalyptic number.

It is an amenable number.

11867821081 is a deficient number, since it is larger than the sum of its proper divisors (1).

11867821081 is an equidigital number, since it uses as much as digits as its factorization.

11867821081 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 43008, while the sum is 43.

The spelling of 11867821081 in words is "eleven billion, eight hundred sixty-seven million, eight hundred twenty-one thousand, eighty-one".