123840569 has 2 divisors, whose sum is σ = 123840570. Its totient is φ = 123840568.

The previous prime is 123840557. The next prime is 123840571. The reversal of 123840569 is 965048321.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 114918400 + 8922169 = 10720^2 + 2987^2 .

It is a cyclic number.

It is not a de Polignac number, because 123840569 - 2⁸ = 123840313 is a prime.

It is a super-2 number, since 2×123840569² = 30672973060487522, which contains 22 as substring.

Together with 123840571, 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 (123840539) 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 as a sum of consecutive naturals, namely, 61920284 + 61920285.

It is an arithmetic number, because the mean of its divisors is an integer number (61920285).

Almost surely, 2^123840569 is an apocalyptic number.

It is an amenable number.

123840569 is a deficient number, since it is larger than the sum of its proper divisors (1).

123840569 is an equidigital number, since it uses as much as digits as its factorization.

123840569 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 51840, while the sum is 38.

The square root of 123840569 is about 11128.3677599188. The cubic root of 123840569 is about 498.4492875538.

The spelling of 123840569 in words is "one hundred twenty-three million, eight hundred forty thousand, five hundred sixty-nine".