11603512561 has 2 divisors, whose sum is σ = 11603512562. Its totient is φ = 11603512560.

The previous prime is 11603512523. The next prime is 11603512573. The reversal of 11603512561 is 16521530611.

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., 11603382961 + 129600 = 107719^2 + 360^2 .

It is a cyclic number.

It is not a de Polignac number, because 11603512561 - 2⁷ = 11603512433 is a prime.

It is not a weakly prime, because it can be changed into another prime (11603510561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5801756280 + 5801756281.

It is an arithmetic number, because the mean of its divisors is an integer number (5801756281).

Almost surely, 2^11603512561 is an apocalyptic number.

It is an amenable number.

11603512561 is a deficient number, since it is larger than the sum of its proper divisors (1).

11603512561 is an equidigital number, since it uses as much as digits as its factorization.

11603512561 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5400, while the sum is 31.

The spelling of 11603512561 in words is "eleven billion, six hundred three million, five hundred twelve thousand, five hundred sixty-one".