11506554236581 has 2 divisors, whose sum is σ = 11506554236582. Its totient is φ = 11506554236580.

The previous prime is 11506554236563. The next prime is 11506554236677. The reversal of 11506554236581 is 18563245560511.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6856777917025 + 4649776319556 = 2618545^2 + 2156334^2 .

It is a cyclic number.

It is not a de Polignac number, because 11506554236581 - 2⁷ = 11506554236453 is a prime.

It is a super-2 number, since 2×11506554236581² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (11506554236521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5753277118290 + 5753277118291.

It is an arithmetic number, because the mean of its divisors is an integer number (5753277118291).

Almost surely, 2^{11506554236581} is an apocalyptic number.

It is an amenable number.

11506554236581 is a deficient number, since it is larger than the sum of its proper divisors (1).

11506554236581 is an equidigital number, since it uses as much as digits as its factorization.

11506554236581 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4320000, while the sum is 52.

The spelling of 11506554236581 in words is "eleven trillion, five hundred six billion, five hundred fifty-four million, two hundred thirty-six thousand, five hundred eighty-one".