123863821 has 2 divisors, whose sum is σ = 123863822. Its totient is φ = 123863820.

The previous prime is 123863791. The next prime is 123863837. The reversal of 123863821 is 128368321.

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., 83997225 + 39866596 = 9165^2 + 6314^2 .

It is a cyclic number.

It is not a de Polignac number, because 123863821 - 2¹⁵ = 123831053 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (123863851) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 61931910 + 61931911.

It is an arithmetic number, because the mean of its divisors is an integer number (61931911).

Almost surely, 2^123863821 is an apocalyptic number.

It is an amenable number.

123863821 is a deficient number, since it is larger than the sum of its proper divisors (1).

123863821 is an equidigital number, since it uses as much as digits as its factorization.

123863821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 13824, while the sum is 34.

The square root of 123863821 is about 11129.4124283360. The cubic root of 123863821 is about 498.4804814715.

The spelling of 123863821 in words is "one hundred twenty-three million, eight hundred sixty-three thousand, eight hundred twenty-one".