126721123 has 2 divisors, whose sum is σ = 126721124. Its totient is φ = 126721122.

The previous prime is 126721117. The next prime is 126721139. The reversal of 126721123 is 321127621.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 126721123 - 2⁹ = 126720611 is a prime.

It is a super-2 number, since 2×126721123² = 32116486028762258, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (126721193) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 63360561 + 63360562.

It is an arithmetic number, because the mean of its divisors is an integer number (63360562).

Almost surely, 2^126721123 is an apocalyptic number.

126721123 is a deficient number, since it is larger than the sum of its proper divisors (1).

126721123 is an equidigital number, since it uses as much as digits as its factorization.

126721123 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1008, while the sum is 25.

The square root of 126721123 is about 11257.0477035500. The cubic root of 126721123 is about 502.2843780066.

Adding to 126721123 its reverse (321127621), we get a palindrome (447848744).

The spelling of 126721123 in words is "one hundred twenty-six million, seven hundred twenty-one thousand, one hundred twenty-three".