21093683 has 4 divisors (see below), whose sum is σ = 22716288. Its totient is φ = 19471080.

The previous prime is 21093661. The next prime is 21093689. The reversal of 21093683 is 38639012.

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

It is a cyclic number.

It is not a de Polignac number, because 21093683 - 2⁸ = 21093427 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21093689) 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 in 3 ways as a sum of consecutive naturals, for example, 811283 + ... + 811308.

It is an arithmetic number, because the mean of its divisors is an integer number (5679072).

Almost surely, 2^21093683 is an apocalyptic number.

21093683 is a deficient number, since it is larger than the sum of its proper divisors (1622605).

21093683 is a wasteful number, since it uses less digits than its factorization.

21093683 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1622604.

The product of its (nonzero) digits is 7776, while the sum is 32.

The square root of 21093683 is about 4592.7859736765. The cubic root of 21093683 is about 276.3020698583.

The spelling of 21093683 in words is "twenty-one million, ninety-three thousand, six hundred eighty-three".