123607721 has 2 divisors, whose sum is σ = 123607722. Its totient is φ = 123607720.

The previous prime is 123607699. The next prime is 123607733. The reversal of 123607721 is 127706321.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 78234025 + 45373696 = 8845^2 + 6736^2 .

It is an emirp because it is prime and its reverse (127706321) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 123607721 - 2¹⁰ = 123606697 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (123607741) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 61803860 + 61803861.

It is an arithmetic number, because the mean of its divisors is an integer number (61803861).

Almost surely, 2^123607721 is an apocalyptic number.

It is an amenable number.

123607721 is a deficient number, since it is larger than the sum of its proper divisors (1).

123607721 is an equidigital number, since it uses as much as digits as its factorization.

123607721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3528, while the sum is 29.

The square root of 123607721 is about 11117.9009259842. The cubic root of 123607721 is about 498.1366927982.

The spelling of 123607721 in words is "one hundred twenty-three million, six hundred seven thousand, seven hundred twenty-one".