126720289 has 4 divisors (see below), whose sum is σ = 126763056. Its totient is φ = 126677524.

The previous prime is 126720277. The next prime is 126720313. The reversal of 126720289 is 982027621.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 982027621 = 157 ⋅6254953.

It is a cyclic number.

It is not a de Polignac number, because 126720289 - 2⁹ = 126719777 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (126720389) 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 3 ways as a sum of consecutive naturals, for example, 16579 + ... + 22984.

It is an arithmetic number, because the mean of its divisors is an integer number (31690764).

Almost surely, 2^126720289 is an apocalyptic number.

It is an amenable number.

126720289 is a deficient number, since it is larger than the sum of its proper divisors (42767).

126720289 is an equidigital number, since it uses as much as digits as its factorization.

126720289 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42766.

The product of its (nonzero) digits is 24192, while the sum is 37.

The square root of 126720289 is about 11257.0106600287. The cubic root of 126720289 is about 502.2832760959.

The spelling of 126720289 in words is "one hundred twenty-six million, seven hundred twenty thousand, two hundred eighty-nine".