11506554236521 has 2 divisors, whose sum is σ = 11506554236522. Its totient is φ = 11506554236520.

The previous prime is 11506554236491. The next prime is 11506554236533. The reversal of 11506554236521 is 12563245560511.

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., 9992780810496 + 1513773426025 = 3161136^2 + 1230355^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-11506554236521 is a prime.

It is not a weakly prime, because it can be changed into another prime (11506554236581) 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, 5753277118260 + 5753277118261.

It is an arithmetic number, because the mean of its divisors is an integer number (5753277118261).

Almost surely, 2^{11506554236521} is an apocalyptic number.

It is an amenable number.

11506554236521 is a deficient number, since it is larger than the sum of its proper divisors (1).

11506554236521 is an equidigital number, since it uses as much as digits as its factorization.

11506554236521 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1080000, while the sum is 46.

The spelling of 11506554236521 in words is "eleven trillion, five hundred six billion, five hundred fifty-four million, two hundred thirty-six thousand, five hundred twenty-one".