1279696421 has 2 divisors, whose sum is σ = 1279696422. Its totient is φ = 1279696420.

The previous prime is 1279696409. The next prime is 1279696447. The reversal of 1279696421 is 1246969721.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 983512321 + 296184100 = 31361^2 + 17210^2 .

It is a cyclic number.

It is not a de Polignac number, because 1279696421 - 2⁶ = 1279696357 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1279696321) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 639848210 + 639848211.

It is an arithmetic number, because the mean of its divisors is an integer number (639848211).

Almost surely, 2^1279696421 is an apocalyptic number.

It is an amenable number.

1279696421 is a deficient number, since it is larger than the sum of its proper divisors (1).

1279696421 is an equidigital number, since it uses as much as digits as its factorization.

1279696421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 326592, while the sum is 47.

The square root of 1279696421 is about 35772.8447429052. The cubic root of 1279696421 is about 1085.6812023317.

The spelling of 1279696421 in words is "one billion, two hundred seventy-nine million, six hundred ninety-six thousand, four hundred twenty-one".