1224550721 has 2 divisors, whose sum is σ = 1224550722. Its totient is φ = 1224550720.

The previous prime is 1224550711. The next prime is 1224550727. The reversal of 1224550721 is 1270554221.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1015314496 + 209236225 = 31864^2 + 14465^2 .

It is an emirp because it is prime and its reverse (1270554221) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1224550721 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 (1224550727) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 612275360 + 612275361.

It is an arithmetic number, because the mean of its divisors is an integer number (612275361).

Almost surely, 2^1224550721 is an apocalyptic number.

It is an amenable number.

1224550721 is a deficient number, since it is larger than the sum of its proper divisors (1).

1224550721 is an equidigital number, since it uses as much as digits as its factorization.

1224550721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5600, while the sum is 29.

The square root of 1224550721 is about 34993.5811399748. The cubic root of 1224550721 is about 1069.8566556162.

The spelling of 1224550721 in words is "one billion, two hundred twenty-four million, five hundred fifty thousand, seven hundred twenty-one".