1278181 has 2 divisors, whose sum is σ = 1278182. Its totient is φ = 1278180.

The previous prime is 1278163. The next prime is 1278191. The reversal of 1278181 is 1818721.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1018081 + 260100 = 1009^2 + 510^2 .

It is an emirp because it is prime and its reverse (1818721) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1278181 - 2¹¹ = 1276133 is a prime.

It is a super-2 number, since 2×1278181² = 3267493337522, which contains 22 as substring.

It is a Chen prime.

It is an alternating number because its digits alternate between odd and even.

1278181 is a lucky number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1278131) by changing a digit.

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 639090 + 639091.

It is an arithmetic number, because the mean of its divisors is an integer number (639091).

2^1278181 is an apocalyptic number.

It is an amenable number.

1278181 is a deficient number, since it is larger than the sum of its proper divisors (1).

1278181 is an equidigital number, since it uses as much as digits as its factorization.

1278181 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 896, while the sum is 28.

The square root of 1278181 is about 1130.5666720720. The cubic root of 1278181 is about 108.5252477222.

The spelling of 1278181 in words is "one million, two hundred seventy-eight thousand, one hundred eighty-one".