142605721 has 2 divisors, whose sum is σ = 142605722. Its totient is φ = 142605720.

The previous prime is 142605709. The next prime is 142605761. The reversal of 142605721 is 127506241.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 135396496 + 7209225 = 11636^2 + 2685^2 .

It is a cyclic number.

It is not a de Polignac number, because 142605721 - 2⁵ = 142605689 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 142605721.

It is not a weakly prime, because it can be changed into another prime (142605761) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 71302860 + 71302861.

It is an arithmetic number, because the mean of its divisors is an integer number (71302861).

Almost surely, 2^142605721 is an apocalyptic number.

It is an amenable number.

142605721 is a deficient number, since it is larger than the sum of its proper divisors (1).

142605721 is an equidigital number, since it uses as much as digits as its factorization.

142605721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3360, while the sum is 28.

The square root of 142605721 is about 11941.7637307058. The cubic root of 142605721 is about 522.4511020074.

The spelling of 142605721 in words is "one hundred forty-two million, six hundred five thousand, seven hundred twenty-one".