126105561 has 12 divisors (see below), whose sum is σ = 182279188. Its totient is φ = 84011904.

The previous prime is 126105557. The next prime is 126105569. The reversal of 126105561 is 165501621.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 6859161 + 119246400 = 2619^2 + 10920^2 .

It is not a de Polignac number, because 126105561 - 2² = 126105557 is a prime.

It is a super-2 number, since 2×126105561² = 31805225030249442, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (126105569) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 11781 + ... + 19773.

Almost surely, 2^126105561 is an apocalyptic number.

It is an amenable number.

126105561 is a deficient number, since it is larger than the sum of its proper divisors (56173627).

126105561 is a wasteful number, since it uses less digits than its factorization.

126105561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9752 (or 9749 counting only the distinct ones).

The product of its (nonzero) digits is 1800, while the sum is 27.

The square root of 126105561 is about 11229.6732365639. The cubic root of 126105561 is about 501.4697567304.

The spelling of 126105561 in words is "one hundred twenty-six million, one hundred five thousand, five hundred sixty-one".