1279225021 has 2 divisors, whose sum is σ = 1279225022. Its totient is φ = 1279225020.

The previous prime is 1279225009. The next prime is 1279225069. The reversal of 1279225021 is 1205229721.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 884408121 + 394816900 = 29739^2 + 19870^2 .

It is a cyclic number.

It is not a de Polignac number, because 1279225021 - 2²⁷ = 1145007293 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1279225001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 639612510 + 639612511.

It is an arithmetic number, because the mean of its divisors is an integer number (639612511).

Almost surely, 2^1279225021 is an apocalyptic number.

It is an amenable number.

1279225021 is a deficient number, since it is larger than the sum of its proper divisors (1).

1279225021 is an equidigital number, since it uses as much as digits as its factorization.

1279225021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5040, while the sum is 31.

The square root of 1279225021 is about 35766.2553393558. The cubic root of 1279225021 is about 1085.5478756651.

The spelling of 1279225021 in words is "one billion, two hundred seventy-nine million, two hundred twenty-five thousand, twenty-one".