27813221 has 2 divisors, whose sum is σ = 27813222. Its totient is φ = 27813220.

The previous prime is 27813209. The next prime is 27813239. The reversal of 27813221 is 12231872.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 23872996 + 3940225 = 4886^2 + 1985^2 .

It is a cyclic number.

It is not a de Polignac number, because 27813221 - 2⁶ = 27813157 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (27813251) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13906610 + 13906611.

It is an arithmetic number, because the mean of its divisors is an integer number (13906611).

Almost surely, 2^27813221 is an apocalyptic number.

It is an amenable number.

27813221 is a deficient number, since it is larger than the sum of its proper divisors (1).

27813221 is an equidigital number, since it uses as much as digits as its factorization.

27813221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1344, while the sum is 26.

The square root of 27813221 is about 5273.8241343450. The cubic root of 27813221 is about 302.9821866105.

The spelling of 27813221 in words is "twenty-seven million, eight hundred thirteen thousand, two hundred twenty-one".