1279726621 has 2 divisors, whose sum is σ = 1279726622. Its totient is φ = 1279726620.

The previous prime is 1279726607. The next prime is 1279726633. The reversal of 1279726621 is 1266279721.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 837465721 + 442260900 = 28939^2 + 21030^2 .

It is a cyclic number.

It is not a de Polignac number, because 1279726621 - 2⁹ = 1279726109 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1279726681) 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, 639863310 + 639863311.

It is an arithmetic number, because the mean of its divisors is an integer number (639863311).

Almost surely, 2^1279726621 is an apocalyptic number.

It is an amenable number.

1279726621 is a deficient number, since it is larger than the sum of its proper divisors (1).

1279726621 is an equidigital number, since it uses as much as digits as its factorization.

1279726621 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 127008, while the sum is 43.

The square root of 1279726621 is about 35773.2668483045. The cubic root of 1279726621 is about 1085.6897427203.

The spelling of 1279726621 in words is "one billion, two hundred seventy-nine million, seven hundred twenty-six thousand, six hundred twenty-one".