1278883189 has 2 divisors, whose sum is σ = 1278883190. Its totient is φ = 1278883188.

The previous prime is 1278883187. The next prime is 1278883201. The reversal of 1278883189 is 9813888721.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 729918289 + 548964900 = 27017^2 + 23430^2 .

It is a cyclic number.

It is not a de Polignac number, because 1278883189 - 2¹ = 1278883187 is a prime.

It is a super-2 number, since 2×1278883189² = 3271084422213619442, which contains 22 as substring.

Together with 1278883187, 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 (1278883183) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 639441594 + 639441595.

It is an arithmetic number, because the mean of its divisors is an integer number (639441595).

Almost surely, 2^1278883189 is an apocalyptic number.

It is an amenable number.

1278883189 is a deficient number, since it is larger than the sum of its proper divisors (1).

1278883189 is an equidigital number, since it uses as much as digits as its factorization.

1278883189 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1548288, while the sum is 55.

The square root of 1278883189 is about 35761.4763257895. The cubic root of 1278883189 is about 1085.4511743934.

The spelling of 1278883189 in words is "one billion, two hundred seventy-eight million, eight hundred eighty-three thousand, one hundred eighty-nine".