27898021 has 2 divisors, whose sum is σ = 27898022. Its totient is φ = 27898020.

The previous prime is 27898019. The next prime is 27898027. The reversal of 27898021 is 12089872.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 25867396 + 2030625 = 5086^2 + 1425^2 .

It is a cyclic number.

It is not a de Polignac number, because 27898021 - 2¹ = 27898019 is a prime.

Together with 27898019, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (27898027) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13949010 + 13949011.

It is an arithmetic number, because the mean of its divisors is an integer number (13949011).

Almost surely, 2^27898021 is an apocalyptic number.

It is an amenable number.

27898021 is a deficient number, since it is larger than the sum of its proper divisors (1).

27898021 is an equidigital number, since it uses as much as digits as its factorization.

27898021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 16128, while the sum is 37.

The square root of 27898021 is about 5281.8577224306. The cubic root of 27898021 is about 303.2897959760.

The spelling of 27898021 in words is "twenty-seven million, eight hundred ninety-eight thousand, twenty-one".