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21321331 is a prime number
BaseRepresentation
bin101000101010…
…1011001110011
31111010020100221
41101111121303
520424240311
62040553511
7346141213
oct121253163
944106327
1021321331
1111043039
127182897
134556995
142b90243
151d12671
hex1455673

21321331 has 2 divisors, whose sum is σ = 21321332. Its totient is φ = 21321330.

The previous prime is 21321301. The next prime is 21321337. The reversal of 21321331 is 13312312.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21321331 - 27 = 21321203 is a prime.

It is a super-2 number, since 2×213213312 = 909198311223122, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21321337) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10660665 + 10660666.

It is an arithmetic number, because the mean of its divisors is an integer number (10660666).

Almost surely, 221321331 is an apocalyptic number.

21321331 is a deficient number, since it is larger than the sum of its proper divisors (1).

21321331 is an equidigital number, since it uses as much as digits as its factorization.

21321331 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 108, while the sum is 16.

The square root of 21321331 is about 4617.5026800209. The cubic root of 21321331 is about 277.2924877759.

Adding to 21321331 its reverse (13312312), we get a palindrome (34633643).

The spelling of 21321331 in words is "twenty-one million, three hundred twenty-one thousand, three hundred thirty-one".