1121563561 has 2 divisors, whose sum is σ = 1121563562. Its totient is φ = 1121563560.

The previous prime is 1121563519. The next prime is 1121563637. The reversal of 1121563561 is 1653651211.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1046134336 + 75429225 = 32344^2 + 8685^2 .

It is a cyclic number.

It is not a de Polignac number, because 1121563561 - 2⁷ = 1121563433 is a prime.

It is not a weakly prime, because it can be changed into another prime (1121533561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 560781780 + 560781781.

It is an arithmetic number, because the mean of its divisors is an integer number (560781781).

Almost surely, 2^1121563561 is an apocalyptic number.

It is an amenable number.

1121563561 is a deficient number, since it is larger than the sum of its proper divisors (1).

1121563561 is an equidigital number, since it uses as much as digits as its factorization.

1121563561 is an evil number, because the sum of its binary digits is even.

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

The square root of 1121563561 is about 33489.7530746346. The cubic root of 1121563561 is about 1038.9818564511.

The spelling of 1121563561 in words is "one billion, one hundred twenty-one million, five hundred sixty-three thousand, five hundred sixty-one".