126212509 has 2 divisors, whose sum is σ = 126212510. Its totient is φ = 126212508.

The previous prime is 126212491. The next prime is 126212521. The reversal of 126212509 is 905212621.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 76510009 + 49702500 = 8747^2 + 7050^2 .

It is a cyclic number.

It is not a de Polignac number, because 126212509 - 2⁹ = 126211997 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (126212549) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 63106254 + 63106255.

It is an arithmetic number, because the mean of its divisors is an integer number (63106255).

Almost surely, 2^126212509 is an apocalyptic number.

It is an amenable number.

126212509 is a deficient number, since it is larger than the sum of its proper divisors (1).

126212509 is an equidigital number, since it uses as much as digits as its factorization.

126212509 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2160, while the sum is 28.

The square root of 126212509 is about 11234.4340756444. The cubic root of 126212509 is about 501.6114793555.

The spelling of 126212509 in words is "one hundred twenty-six million, two hundred twelve thousand, five hundred nine".