20683729 has 4 divisors (see below), whose sum is σ = 22564080. Its totient is φ = 18803380.

The previous prime is 20683717. The next prime is 20683763. The reversal of 20683729 is 92738602.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20683729 - 2¹³ = 20675537 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20683709) 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, 940159 + ... + 940180.

It is an arithmetic number, because the mean of its divisors is an integer number (5641020).

Almost surely, 2^20683729 is an apocalyptic number.

It is an amenable number.

20683729 is a deficient number, since it is larger than the sum of its proper divisors (1880351).

20683729 is a wasteful number, since it uses less digits than its factorization.

20683729 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1880350.

The product of its (nonzero) digits is 36288, while the sum is 37.

The square root of 20683729 is about 4547.9367849608. The cubic root of 20683729 is about 274.5003776802.

It can be divided in two parts, 20683 and 729, that added together give a palindrome (21412).

The spelling of 20683729 in words is "twenty million, six hundred eighty-three thousand, seven hundred twenty-nine".