126261009 has 24 divisors (see below), whose sum is σ = 210505152. Its totient is φ = 71431200.

The previous prime is 126261001. The next prime is 126261049. The reversal of 126261009 is 900162621.

It is not a de Polignac number, because 126261009 - 2³ = 126261001 is a prime.

It is not an unprimeable number, because it can be changed into a prime (126261001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3559 + ... + 16284.

It is an arithmetic number, because the mean of its divisors is an integer number (8771048).

Almost surely, 2^126261009 is an apocalyptic number.

It is an amenable number.

126261009 is a deficient number, since it is larger than the sum of its proper divisors (84244143).

126261009 is a wasteful number, since it uses less digits than its factorization.

126261009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19957 (or 19954 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 27.

The square root of 126261009 is about 11236.5924105131. The cubic root of 126261009 is about 501.6757229644.

The spelling of 126261009 in words is "one hundred twenty-six million, two hundred sixty-one thousand, nine".