1273831021 has 2 divisors, whose sum is σ = 1273831022. Its totient is φ = 1273831020.

The previous prime is 1273831019. The next prime is 1273831087. The reversal of 1273831021 is 1201383721.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1121580100 + 152250921 = 33490^2 + 12339^2 .

It is a cyclic number.

It is not a de Polignac number, because 1273831021 - 2¹ = 1273831019 is a prime.

Together with 1273831019, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1273831721) 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, 636915510 + 636915511.

It is an arithmetic number, because the mean of its divisors is an integer number (636915511).

Almost surely, 2^1273831021 is an apocalyptic number.

It is an amenable number.

1273831021 is a deficient number, since it is larger than the sum of its proper divisors (1).

1273831021 is an equidigital number, since it uses as much as digits as its factorization.

1273831021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2016, while the sum is 28.

The square root of 1273831021 is about 35690.7694089102. The cubic root of 1273831021 is about 1084.0199467674.

The spelling of 1273831021 in words is "one billion, two hundred seventy-three million, eight hundred thirty-one thousand, twenty-one".