1442247721 has 2 divisors, whose sum is σ = 1442247722. Its totient is φ = 1442247720.

The previous prime is 1442247661. The next prime is 1442247727. The reversal of 1442247721 is 1277422441.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1198544400 + 243703321 = 34620^2 + 15611^2 .

It is an emirp because it is prime and its reverse (1277422441) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1442247721 - 2¹⁹ = 1441723433 is a prime.

It is not a weakly prime, because it can be changed into another prime (1442247727) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 721123860 + 721123861.

It is an arithmetic number, because the mean of its divisors is an integer number (721123861).

Almost surely, 2^1442247721 is an apocalyptic number.

It is an amenable number.

1442247721 is a deficient number, since it is larger than the sum of its proper divisors (1).

1442247721 is an equidigital number, since it uses as much as digits as its factorization.

1442247721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 25088, while the sum is 34.

The square root of 1442247721 is about 37976.9366984753. The cubic root of 1442247721 is about 1129.8304810054.

The spelling of 1442247721 in words is "one billion, four hundred forty-two million, two hundred forty-seven thousand, seven hundred twenty-one".