123666251 has 2 divisors, whose sum is σ = 123666252. Its totient is φ = 123666250.

The previous prime is 123666233. The next prime is 123666253. The reversal of 123666251 is 152666321.

It is a strong prime.

It is an emirp because it is prime and its reverse (152666321) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 123666251 - 2⁶ = 123666187 is a prime.

Together with 123666253, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (123666253) by changing a digit.

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 61833125 + 61833126.

It is an arithmetic number, because the mean of its divisors is an integer number (61833126).

Almost surely, 2^123666251 is an apocalyptic number.

123666251 is a deficient number, since it is larger than the sum of its proper divisors (1).

123666251 is an equidigital number, since it uses as much as digits as its factorization.

123666251 is an evil number, because the sum of its binary digits is even.

The product of its digits is 12960, while the sum is 32.

The square root of 123666251 is about 11120.5328559382. The cubic root of 123666251 is about 498.2153053090.

The spelling of 123666251 in words is "one hundred twenty-three million, six hundred sixty-six thousand, two hundred fifty-one".