21020227 has 2 divisors, whose sum is σ = 21020228. Its totient is φ = 21020226.

The previous prime is 21020161. The next prime is 21020231. The reversal of 21020227 is 72202012.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21020227 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21020227.

It is not a weakly prime, because it can be changed into another prime (21020267) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10510113 + 10510114.

It is an arithmetic number, because the mean of its divisors is an integer number (10510114).

Almost surely, 2^21020227 is an apocalyptic number.

21020227 is a deficient number, since it is larger than the sum of its proper divisors (1).

21020227 is an equidigital number, since it uses as much as digits as its factorization.

21020227 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 112, while the sum is 16.

The square root of 21020227 is about 4584.7821104170. The cubic root of 21020227 is about 275.9809681969.

Adding to 21020227 its reverse (72202012), we get a palindrome (93222239).

The spelling of 21020227 in words is "twenty-one million, twenty thousand, two hundred twenty-seven".