20691683 has 4 divisors (see below), whose sum is σ = 20749680. Its totient is φ = 20633688.

The previous prime is 20691667. The next prime is 20691691. The reversal of 20691683 is 38619602.

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 20691683 - 2⁴ = 20691667 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20691613) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 28460 + ... + 29177.

It is an arithmetic number, because the mean of its divisors is an integer number (5187420).

Almost surely, 2^20691683 is an apocalyptic number.

20691683 is a deficient number, since it is larger than the sum of its proper divisors (57997).

20691683 is an equidigital number, since it uses as much as digits as its factorization.

20691683 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57996.

The product of its (nonzero) digits is 15552, while the sum is 35.

The square root of 20691683 is about 4548.8111633701. The cubic root of 20691683 is about 274.5355598627.

The spelling of 20691683 in words is "twenty million, six hundred ninety-one thousand, six hundred eighty-three".