21364747 has 2 divisors, whose sum is σ = 21364748. Its totient is φ = 21364746.

The previous prime is 21364727. The next prime is 21364771. The reversal of 21364747 is 74746312.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21364747 - 2¹⁹ = 20840459 is a prime.

It is not a weakly prime, because it can be changed into another prime (21364727) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10682373 + 10682374.

It is an arithmetic number, because the mean of its divisors is an integer number (10682374).

Almost surely, 2^21364747 is an apocalyptic number.

21364747 is a deficient number, since it is larger than the sum of its proper divisors (1).

21364747 is an equidigital number, since it uses as much as digits as its factorization.

21364747 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 28224, while the sum is 34.

The square root of 21364747 is about 4622.2015317379. The cubic root of 21364747 is about 277.4805743510.

The spelling of 21364747 in words is "twenty-one million, three hundred sixty-four thousand, seven hundred forty-seven".