123136621 has 2 divisors, whose sum is σ = 123136622. Its totient is φ = 123136620.

The previous prime is 123136609. The next prime is 123136679. The reversal of 123136621 is 126631321.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 82355625 + 40780996 = 9075^2 + 6386^2 .

It is a cyclic number.

It is not a de Polignac number, because 123136621 - 2⁷ = 123136493 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (123136691) 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, 61568310 + 61568311.

It is an arithmetic number, because the mean of its divisors is an integer number (61568311).

Almost surely, 2^123136621 is an apocalyptic number.

It is an amenable number.

123136621 is a deficient number, since it is larger than the sum of its proper divisors (1).

123136621 is an equidigital number, since it uses as much as digits as its factorization.

123136621 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1296, while the sum is 25.

The square root of 123136621 is about 11096.6941473576. The cubic root of 123136621 is about 497.5030458640.

Adding to 123136621 its reverse (126631321), we get a palindrome (249767942).

The spelling of 123136621 in words is "one hundred twenty-three million, one hundred thirty-six thousand, six hundred twenty-one".