123555749 has 2 divisors, whose sum is σ = 123555750. Its totient is φ = 123555748.

The previous prime is 123555743. The next prime is 123555767. The reversal of 123555749 is 947555321.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 120340900 + 3214849 = 10970^2 + 1793^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-123555749 is a prime.

It is a super-2 number, since 2×123555749² = 30532046221902002, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (123555743) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 61777874 + 61777875.

It is an arithmetic number, because the mean of its divisors is an integer number (61777875).

Almost surely, 2^123555749 is an apocalyptic number.

It is an amenable number.

123555749 is a deficient number, since it is larger than the sum of its proper divisors (1).

123555749 is an equidigital number, since it uses as much as digits as its factorization.

123555749 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 189000, while the sum is 41.

The square root of 123555749 is about 11115.5633685387. The cubic root of 123555749 is about 498.0668676306.

The spelling of 123555749 in words is "one hundred twenty-three million, five hundred fifty-five thousand, seven hundred forty-nine".