1278538841 has 2 divisors, whose sum is σ = 1278538842. Its totient is φ = 1278538840.

The previous prime is 1278538837. The next prime is 1278538867. The reversal of 1278538841 is 1488358721.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1265865241 + 12673600 = 35579^2 + 3560^2 .

It is a cyclic number.

It is not a de Polignac number, because 1278538841 - 2² = 1278538837 is a prime.

It is not a weakly prime, because it can be changed into another prime (1278538801) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 639269420 + 639269421.

It is an arithmetic number, because the mean of its divisors is an integer number (639269421).

Almost surely, 2^1278538841 is an apocalyptic number.

It is an amenable number.

1278538841 is a deficient number, since it is larger than the sum of its proper divisors (1).

1278538841 is an equidigital number, since it uses as much as digits as its factorization.

1278538841 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 430080, while the sum is 47.

The square root of 1278538841 is about 35756.6614912522. The cubic root of 1278538841 is about 1085.3537439436.

The spelling of 1278538841 in words is "one billion, two hundred seventy-eight million, five hundred thirty-eight thousand, eight hundred forty-one".