1115651561 has 2 divisors, whose sum is σ = 1115651562. Its totient is φ = 1115651560.

The previous prime is 1115651543. The next prime is 1115651567. The reversal of 1115651561 is 1651565111.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 806560000 + 309091561 = 28400^2 + 17581^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1115651561 is a prime.

It is not a weakly prime, because it can be changed into another prime (1115651567) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 557825780 + 557825781.

It is an arithmetic number, because the mean of its divisors is an integer number (557825781).

Almost surely, 2^1115651561 is an apocalyptic number.

It is an amenable number.

1115651561 is a deficient number, since it is larger than the sum of its proper divisors (1).

1115651561 is an equidigital number, since it uses as much as digits as its factorization.

1115651561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4500, while the sum is 32.

The square root of 1115651561 is about 33401.3706455289. The cubic root of 1115651561 is about 1037.1530746190.

The spelling of 1115651561 in words is "one billion, one hundred fifteen million, six hundred fifty-one thousand, five hundred sixty-one".