21360223 has 2 divisors, whose sum is σ = 21360224. Its totient is φ = 21360222.

The previous prime is 21360197. The next prime is 21360233. The reversal of 21360223 is 32206312.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21360223 - 2⁵ = 21360191 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21360223.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21360233) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10680111 + 10680112.

It is an arithmetic number, because the mean of its divisors is an integer number (10680112).

Almost surely, 2^21360223 is an apocalyptic number.

21360223 is a deficient number, since it is larger than the sum of its proper divisors (1).

21360223 is an equidigital number, since it uses as much as digits as its factorization.

21360223 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 432, while the sum is 19.

The square root of 21360223 is about 4621.7121286380. The cubic root of 21360223 is about 277.4609874004.

Adding to 21360223 its reverse (32206312), we get a palindrome (53566535).

The spelling of 21360223 in words is "twenty-one million, three hundred sixty thousand, two hundred twenty-three".