21369223 has 2 divisors, whose sum is σ = 21369224. Its totient is φ = 21369222.

The previous prime is 21369211. The next prime is 21369247. The reversal of 21369223 is 32296312.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21369223 - 2¹³ = 21361031 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21369191 and 21369200.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21369253) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10684611 + 10684612.

It is an arithmetic number, because the mean of its divisors is an integer number (10684612).

Almost surely, 2^21369223 is an apocalyptic number.

21369223 is a deficient number, since it is larger than the sum of its proper divisors (1).

21369223 is an equidigital number, since it uses as much as digits as its factorization.

21369223 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3888, while the sum is 28.

The square root of 21369223 is about 4622.6856912405. The cubic root of 21369223 is about 277.4999507616.

The spelling of 21369223 in words is "twenty-one million, three hundred sixty-nine thousand, two hundred twenty-three".