123442721 has 2 divisors, whose sum is σ = 123442722. Its totient is φ = 123442720.

The previous prime is 123442699. The next prime is 123442751. The reversal of 123442721 is 127244321.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 115240225 + 8202496 = 10735^2 + 2864^2 .

It is a cyclic number.

It is not a de Polignac number, because 123442721 - 2¹⁰ = 123441697 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (123442751) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 61721360 + 61721361.

It is an arithmetic number, because the mean of its divisors is an integer number (61721361).

Almost surely, 2^123442721 is an apocalyptic number.

It is an amenable number.

123442721 is a deficient number, since it is larger than the sum of its proper divisors (1).

123442721 is an equidigital number, since it uses as much as digits as its factorization.

123442721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2688, while the sum is 26.

The square root of 123442721 is about 11110.4779825172. The cubic root of 123442721 is about 497.9149451790.

The spelling of 123442721 in words is "one hundred twenty-three million, four hundred forty-two thousand, seven hundred twenty-one".