21350223 has 14 divisors (see below), whose sum is σ = 32011784. Its totient is φ = 14232996.

The previous prime is 21350213. The next prime is 21350291. The reversal of 21350223 is 32205312.

It is not a de Polignac number, because 21350223 - 2⁶ = 21350159 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21350196 and 21350205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21350213) by changing a digit.

It is a polite number, since it can be written in 13 ways as a sum of consecutive naturals, for example, 13915 + ... + 15372.

It is an arithmetic number, because the mean of its divisors is an integer number (2286556).

Almost surely, 2^21350223 is an apocalyptic number.

21350223 is a deficient number, since it is larger than the sum of its proper divisors (10661561).

21350223 is an frugal number, since it uses more digits than its factorization.

21350223 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29305 (or 29290 counting only the distinct ones).

The product of its (nonzero) digits is 360, while the sum is 18.

The square root of 21350223 is about 4620.6301518299. The cubic root of 21350223 is about 277.4176819385.

Adding to 21350223 its reverse (32205312), we get a palindrome (53555535).

The spelling of 21350223 in words is "twenty-one million, three hundred fifty thousand, two hundred twenty-three".