1379227721 has 2 divisors, whose sum is σ = 1379227722. Its totient is φ = 1379227720.

The previous prime is 1379227699. The next prime is 1379227723. The reversal of 1379227721 is 1277229731.

1379227721 = 26260² + 26261².

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 689640121 + 689587600 = 26261^2 + 26260^2 .

It is a cyclic number.

It is not a de Polignac number, because 1379227721 - 2⁶ = 1379227657 is a prime.

It is a Sophie Germain prime.

Together with 1379227723, 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 (1379227723) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 689613860 + 689613861.

It is an arithmetic number, because the mean of its divisors is an integer number (689613861).

Almost surely, 2^1379227721 is an apocalyptic number.

1379227721 is the 26261-st centered square number.

It is an amenable number.

1379227721 is a deficient number, since it is larger than the sum of its proper divisors (1).

1379227721 is an equidigital number, since it uses as much as digits as its factorization.

1379227721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 74088, while the sum is 41.

The square root of 1379227721 is about 37137.9552614303. The cubic root of 1379227721 is about 1113.1285601033.

The spelling of 1379227721 in words is "one billion, three hundred seventy-nine million, two hundred twenty-seven thousand, seven hundred twenty-one".