113603521561 has 2 divisors, whose sum is σ = 113603521562. Its totient is φ = 113603521560.

The previous prime is 113603521543. The next prime is 113603521567. The reversal of 113603521561 is 165125306311.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 82444211161 + 31159310400 = 287131^2 + 176520^2 .

It is a cyclic number.

It is not a de Polignac number, because 113603521561 - 2¹⁵ = 113603488793 is a prime.

It is a super-2 number, since 2×113603521561² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (113603521567) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 56801760780 + 56801760781.

It is an arithmetic number, because the mean of its divisors is an integer number (56801760781).

Almost surely, 2^113603521561 is an apocalyptic number.

It is an amenable number.

113603521561 is a deficient number, since it is larger than the sum of its proper divisors (1).

113603521561 is an equidigital number, since it uses as much as digits as its factorization.

113603521561 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 16200, while the sum is 34.

Adding to 113603521561 its reverse (165125306311), we get a palindrome (278728827872).

The spelling of 113603521561 in words is "one hundred thirteen billion, six hundred three million, five hundred twenty-one thousand, five hundred sixty-one".