27878321 has 2 divisors, whose sum is σ = 27878322. Its totient is φ = 27878320.

The previous prime is 27878299. The next prime is 27878329. The reversal of 27878321 is 12387872.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20802721 + 7075600 = 4561^2 + 2660^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-27878321 is a prime.

It is a Sophie Germain prime.

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

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (27878329) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13939160 + 13939161.

It is an arithmetic number, because the mean of its divisors is an integer number (13939161).

Almost surely, 2^27878321 is an apocalyptic number.

It is an amenable number.

27878321 is a deficient number, since it is larger than the sum of its proper divisors (1).

27878321 is an equidigital number, since it uses as much as digits as its factorization.

27878321 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 37632, while the sum is 38.

The square root of 27878321 is about 5279.9925189341. The cubic root of 27878321 is about 303.2183904823.

The spelling of 27878321 in words is "twenty-seven million, eight hundred seventy-eight thousand, three hundred twenty-one".