1244746721 has 2 divisors, whose sum is σ = 1244746722. Its totient is φ = 1244746720.

The previous prime is 1244746717. The next prime is 1244746733. The reversal of 1244746721 is 1276474421.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1112956321 + 131790400 = 33361^2 + 11480^2 .

It is an emirp because it is prime and its reverse (1276474421) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1244746721 - 2² = 1244746717 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (1244746771) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 622373360 + 622373361.

It is an arithmetic number, because the mean of its divisors is an integer number (622373361).

Almost surely, 2^1244746721 is an apocalyptic number.

It is an amenable number.

1244746721 is a deficient number, since it is larger than the sum of its proper divisors (1).

1244746721 is an equidigital number, since it uses as much as digits as its factorization.

1244746721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 75264, while the sum is 38.

The square root of 1244746721 is about 35280.9682548538. The cubic root of 1244746721 is about 1075.7061798803.

The spelling of 1244746721 in words is "one billion, two hundred forty-four million, seven hundred forty-six thousand, seven hundred twenty-one".