20828009 has 8 divisors (see below), whose sum is σ = 23214240. Its totient is φ = 18570816.

The previous prime is 20827999. The next prime is 20828029. The reversal of 20828009 is 90082802.

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

It is a cyclic number.

It is not a de Polignac number, because 20828009 - 2¹⁶ = 20762473 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20828029) 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, 31919 + ... + 32564.

It is an arithmetic number, because the mean of its divisors is an integer number (2901780).

Almost surely, 2^20828009 is an apocalyptic number.

It is an amenable number.

20828009 is a deficient number, since it is larger than the sum of its proper divisors (2386231).

20828009 is a wasteful number, since it uses less digits than its factorization.

20828009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 64519.

The product of its (nonzero) digits is 2304, while the sum is 29.

The square root of 20828009 is about 4563.7713571124. The cubic root of 20828009 is about 275.1371613289.

The spelling of 20828009 in words is "twenty million, eight hundred twenty-eight thousand, nine".