126210066721 has 16 divisors (see below), whose sum is σ = 128158002000. Its totient is φ = 124277760000.

The previous prime is 126210066709. The next prime is 126210066737. The reversal of 126210066721 is 127660012621.

It can be written as a sum of positive squares in 8 ways, for example, as 25101966096 + 101108100625 = 158436^2 + 317975^2 .

It is a cyclic number.

It is not a de Polignac number, because 126210066721 - 2²⁵ = 126176512289 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (126210066781) 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 in 15 ways as a sum of consecutive naturals, for example, 14130385 + ... + 14139313.

It is an arithmetic number, because the mean of its divisors is an integer number (8009875125).

Almost surely, 2^126210066721 is an apocalyptic number.

It is an amenable number.

126210066721 is a deficient number, since it is larger than the sum of its proper divisors (1947935279).

126210066721 is a wasteful number, since it uses less digits than its factorization.

126210066721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9780.

The product of its (nonzero) digits is 12096, while the sum is 34.

The spelling of 126210066721 in words is "one hundred twenty-six billion, two hundred ten million, sixty-six thousand, seven hundred twenty-one".