123720869 has 2 divisors, whose sum is σ = 123720870. Its totient is φ = 123720868.

The previous prime is 123720853. The next prime is 123720893. The reversal of 123720869 is 968027321.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 119464900 + 4255969 = 10930^2 + 2063^2 .

It is a cyclic number.

It is not a de Polignac number, because 123720869 - 2⁴ = 123720853 is a prime.

It is a super-2 number, since 2×123720869² = 30613706852230322, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (123720899) 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, 61860434 + 61860435.

It is an arithmetic number, because the mean of its divisors is an integer number (61860435).

Almost surely, 2^123720869 is an apocalyptic number.

It is an amenable number.

123720869 is a deficient number, since it is larger than the sum of its proper divisors (1).

123720869 is an equidigital number, since it uses as much as digits as its factorization.

123720869 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 36288, while the sum is 38.

The square root of 123720869 is about 11122.9883124995. The cubic root of 123720869 is about 498.2886411849.

The spelling of 123720869 in words is "one hundred twenty-three million, seven hundred twenty thousand, eight hundred sixty-nine".