1278422851 has 2 divisors, whose sum is σ = 1278422852. Its totient is φ = 1278422850.

The previous prime is 1278422837. The next prime is 1278422861. The reversal of 1278422851 is 1582248721.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1278422851 - 2¹⁷ = 1278291779 is a prime.

It is not a weakly prime, because it can be changed into another prime (1278422861) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 639211425 + 639211426.

It is an arithmetic number, because the mean of its divisors is an integer number (639211426).

Almost surely, 2^1278422851 is an apocalyptic number.

1278422851 is a deficient number, since it is larger than the sum of its proper divisors (1).

1278422851 is an equidigital number, since it uses as much as digits as its factorization.

1278422851 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 71680, while the sum is 40.

The square root of 1278422851 is about 35755.0395189266. The cubic root of 1278422851 is about 1085.3209215832.

The spelling of 1278422851 in words is "one billion, two hundred seventy-eight million, four hundred twenty-two thousand, eight hundred fifty-one".