21473269 has 2 divisors, whose sum is σ = 21473270. Its totient is φ = 21473268.

The previous prime is 21473267. The next prime is 21473273. The reversal of 21473269 is 96237412.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15288100 + 6185169 = 3910^2 + 2487^2 .

It is a cyclic number.

It is not a de Polignac number, because 21473269 - 2¹ = 21473267 is a prime.

It is a super-2 number, since 2×21473269² = 922202563092722, which contains 22 as substring.

Together with 21473267, 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 (21473267) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10736634 + 10736635.

It is an arithmetic number, because the mean of its divisors is an integer number (10736635).

Almost surely, 2^21473269 is an apocalyptic number.

It is an amenable number.

21473269 is a deficient number, since it is larger than the sum of its proper divisors (1).

21473269 is an equidigital number, since it uses as much as digits as its factorization.

21473269 is an evil number, because the sum of its binary digits is even.

The product of its digits is 18144, while the sum is 34.

The square root of 21473269 is about 4633.9258733821. The cubic root of 21473269 is about 277.9496009597.

The spelling of 21473269 in words is "twenty-one million, four hundred seventy-three thousand, two hundred sixty-nine".