1244008721 has 2 divisors, whose sum is σ = 1244008722. Its totient is φ = 1244008720.

The previous prime is 1244008699. The next prime is 1244008723. The reversal of 1244008721 is 1278004421.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 872907025 + 371101696 = 29545^2 + 19264^2 .

It is a cyclic number.

It is not a de Polignac number, because 1244008721 - 2⁶ = 1244008657 is a prime.

It is a Sophie Germain prime.

Together with 1244008723, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (1244008723) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 622004360 + 622004361.

It is an arithmetic number, because the mean of its divisors is an integer number (622004361).

Almost surely, 2^1244008721 is an apocalyptic number.

It is an amenable number.

1244008721 is a deficient number, since it is larger than the sum of its proper divisors (1).

1244008721 is an equidigital number, since it uses as much as digits as its factorization.

1244008721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3584, while the sum is 29.

The square root of 1244008721 is about 35270.5078075153. The cubic root of 1244008721 is about 1075.4935454296.

The spelling of 1244008721 in words is "one billion, two hundred forty-four million, eight thousand, seven hundred twenty-one".