27921281 has 2 divisors, whose sum is σ = 27921282. Its totient is φ = 27921280.

The previous prime is 27921277. The next prime is 27921367. The reversal of 27921281 is 18212972.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 27920656 + 625 = 5284^2 + 25^2 .

It is a cyclic number.

It is not a de Polignac number, because 27921281 - 2² = 27921277 is a prime.

It is a super-2 number, since 2×27921281² = 1559195865361922, which contains 22 as substring.

It is equal to p_1736852 and since 27921281 and 1736852 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (27921221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13960640 + 13960641.

It is an arithmetic number, because the mean of its divisors is an integer number (13960641).

Almost surely, 2^27921281 is an apocalyptic number.

It is an amenable number.

27921281 is a deficient number, since it is larger than the sum of its proper divisors (1).

27921281 is an equidigital number, since it uses as much as digits as its factorization.

27921281 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4032, while the sum is 32.

The square root of 27921281 is about 5284.0591404715. The cubic root of 27921281 is about 303.3740619411.

The spelling of 27921281 in words is "twenty-seven million, nine hundred twenty-one thousand, two hundred eighty-one".