126666257 has 4 divisors (see below), whose sum is σ = 127073856. Its totient is φ = 126258660.

The previous prime is 126666251. The next prime is 126666259. The reversal of 126666257 is 752666621.

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.

It is a cyclic number.

It is not a de Polignac number, because 126666257 - 2⁶ = 126666193 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (126666251) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 203333 + ... + 203954.

It is an arithmetic number, because the mean of its divisors is an integer number (31768464).

Almost surely, 2^126666257 is an apocalyptic number.

It is an amenable number.

126666257 is a deficient number, since it is larger than the sum of its proper divisors (407599).

126666257 is an equidigital number, since it uses as much as digits as its factorization.

126666257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 407598.

The product of its digits is 181440, while the sum is 41.

The square root of 126666257 is about 11254.6104774888. The cubic root of 126666257 is about 502.2118767738.

The spelling of 126666257 in words is "one hundred twenty-six million, six hundred sixty-six thousand, two hundred fifty-seven".