1279439851 has 2 divisors, whose sum is σ = 1279439852. Its totient is φ = 1279439850.

The previous prime is 1279439827. The next prime is 1279439867. The reversal of 1279439851 is 1589349721.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1279439851 - 2⁷ = 1279439723 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1279439795 and 1279439804.

It is not a weakly prime, because it can be changed into another prime (1279439801) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 639719925 + 639719926.

It is an arithmetic number, because the mean of its divisors is an integer number (639719926).

Almost surely, 2^1279439851 is an apocalyptic number.

1279439851 is a deficient number, since it is larger than the sum of its proper divisors (1).

1279439851 is an equidigital number, since it uses as much as digits as its factorization.

1279439851 is an evil number, because the sum of its binary digits is even.

The product of its digits is 544320, while the sum is 49.

The square root of 1279439851 is about 35769.2584630993. The cubic root of 1279439851 is about 1085.6086403710.

The spelling of 1279439851 in words is "one billion, two hundred seventy-nine million, four hundred thirty-nine thousand, eight hundred fifty-one".