123133721 has 2 divisors, whose sum is σ = 123133722. Its totient is φ = 123133720.

The previous prime is 123133711. The next prime is 123133723. The reversal of 123133721 is 127331321.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 107412496 + 15721225 = 10364^2 + 3965^2 .

It is a cyclic number.

It is not a de Polignac number, because 123133721 - 2¹⁸ = 122871577 is a prime.

Together with 123133723, 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 (123133723) 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, 61566860 + 61566861.

It is an arithmetic number, because the mean of its divisors is an integer number (61566861).

Almost surely, 2^123133721 is an apocalyptic number.

It is an amenable number.

123133721 is a deficient number, since it is larger than the sum of its proper divisors (1).

123133721 is an equidigital number, since it uses as much as digits as its factorization.

123133721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 756, while the sum is 23.

The square root of 123133721 is about 11096.5634770410. The cubic root of 123133721 is about 497.4991402559.

The spelling of 123133721 in words is "one hundred twenty-three million, one hundred thirty-three thousand, seven hundred twenty-one".