21084269 has 2 divisors, whose sum is σ = 21084270. Its totient is φ = 21084268.

The previous prime is 21084263. The next prime is 21084289. The reversal of 21084269 is 96248012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16080100 + 5004169 = 4010^2 + 2237^2 .

It is a cyclic number.

It is not a de Polignac number, because 21084269 - 2⁴ = 21084253 is a prime.

It is a super-2 number, since 2×21084269² = 889092798528722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21084263) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10542134 + 10542135.

It is an arithmetic number, because the mean of its divisors is an integer number (10542135).

Almost surely, 2^21084269 is an apocalyptic number.

It is an amenable number.

21084269 is a deficient number, since it is larger than the sum of its proper divisors (1).

21084269 is an equidigital number, since it uses as much as digits as its factorization.

21084269 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6912, while the sum is 32.

The square root of 21084269 is about 4591.7609911667. The cubic root of 21084269 is about 276.2609596875.

The spelling of 21084269 in words is "twenty-one million, eighty-four thousand, two hundred sixty-nine".