21183247 has 2 divisors, whose sum is σ = 21183248. Its totient is φ = 21183246.

The previous prime is 21183223. The next prime is 21183251. The reversal of 21183247 is 74238112.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21183247 - 2¹⁹ = 20658959 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21193247) 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, 10591623 + 10591624.

It is an arithmetic number, because the mean of its divisors is an integer number (10591624).

Almost surely, 2^21183247 is an apocalyptic number.

21183247 is a deficient number, since it is larger than the sum of its proper divisors (1).

21183247 is an equidigital number, since it uses as much as digits as its factorization.

21183247 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2688, while the sum is 28.

The square root of 21183247 is about 4602.5261541897. The cubic root of 21183247 is about 276.6925781767.

The spelling of 21183247 in words is "twenty-one million, one hundred eighty-three thousand, two hundred forty-seven".