27905021 has 2 divisors, whose sum is σ = 27905022. Its totient is φ = 27905020.

The previous prime is 27904967. The next prime is 27905039. The reversal of 27905021 is 12050972.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 26112100 + 1792921 = 5110^2 + 1339^2 .

It is a cyclic number.

It is not a de Polignac number, because 27905021 - 2¹⁸ = 27642877 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 (27905081) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13952510 + 13952511.

It is an arithmetic number, because the mean of its divisors is an integer number (13952511).

Almost surely, 2^27905021 is an apocalyptic number.

It is an amenable number.

27905021 is a deficient number, since it is larger than the sum of its proper divisors (1).

27905021 is an equidigital number, since it uses as much as digits as its factorization.

27905021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1260, while the sum is 26.

The square root of 27905021 is about 5282.5203265108. The cubic root of 27905021 is about 303.3151603920.

Adding to 27905021 its reverse (12050972), we get a palindrome (39955993).

The spelling of 27905021 in words is "twenty-seven million, nine hundred five thousand, twenty-one".