21393683 has 2 divisors, whose sum is σ = 21393684. Its totient is φ = 21393682.

The previous prime is 21393653. The next prime is 21393707. The reversal of 21393683 is 38639312.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21393683 - 2¹⁰ = 21392659 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21393623) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10696841 + 10696842.

It is an arithmetic number, because the mean of its divisors is an integer number (10696842).

Almost surely, 2^21393683 is an apocalyptic number.

21393683 is a deficient number, since it is larger than the sum of its proper divisors (1).

21393683 is an equidigital number, since it uses as much as digits as its factorization.

21393683 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 23328, while the sum is 35.

The square root of 21393683 is about 4625.3305827800. The cubic root of 21393683 is about 277.6057892790.

The spelling of 21393683 in words is "twenty-one million, three hundred ninety-three thousand, six hundred eighty-three".