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21323213 = 113188701
BaseRepresentation
bin101000101010…
…1110111001101
31111010022221122
41101111313031
520424320323
62041010325
7346146542
oct121256715
944108848
1021323213
111104449a
1271839a5
1345577b2
142b90bc9
151d12ec8
hex1455dcd

21323213 has 4 divisors (see below), whose sum is σ = 21512028. Its totient is φ = 21134400.

The previous prime is 21323209. The next prime is 21323261. The reversal of 21323213 is 31232312.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 7912969 + 13410244 = 2813^2 + 3662^2 .

It is a cyclic number.

It is not a de Polignac number, because 21323213 - 22 = 21323209 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21323191 and 21323200.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21323273) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 94238 + ... + 94463.

It is an arithmetic number, because the mean of its divisors is an integer number (5378007).

Almost surely, 221323213 is an apocalyptic number.

It is an amenable number.

21323213 is a deficient number, since it is larger than the sum of its proper divisors (188815).

21323213 is a wasteful number, since it uses less digits than its factorization.

21323213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 188814.

The product of its digits is 216, while the sum is 17.

The square root of 21323213 is about 4617.7064653354. The cubic root of 21323213 is about 277.3006462583.

Adding to 21323213 its reverse (31232312), we get a palindrome (52555525).

Subtracting 21323213 from its reverse (31232312), we obtain a palindrome (9909099).

The spelling of 21323213 in words is "twenty-one million, three hundred twenty-three thousand, two hundred thirteen".

Divisors: 1 113 188701 21323213