20809029 has 8 divisors (see below), whose sum is σ = 28640512. Its totient is φ = 13425120.

The previous prime is 20808989. The next prime is 20809049. The reversal of 20809029 is 92090802.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 20809029 - 2¹² = 20804933 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20808987 and 20809005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20809049) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 111784 + ... + 111969.

It is an arithmetic number, because the mean of its divisors is an integer number (3580064).

Almost surely, 2^20809029 is an apocalyptic number.

It is an amenable number.

20809029 is a deficient number, since it is larger than the sum of its proper divisors (7831483).

20809029 is a wasteful number, since it uses less digits than its factorization.

20809029 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 223787.

The product of its (nonzero) digits is 2592, while the sum is 30.

The square root of 20809029 is about 4561.6914626046. The cubic root of 20809029 is about 275.0535609173.

The spelling of 20809029 in words is "twenty million, eight hundred nine thousand, twenty-nine".