20825709 has 16 divisors (see below), whose sum is σ = 28651392. Its totient is φ = 13445568.

The previous prime is 20825699. The next prime is 20825713. The reversal of 20825709 is 90752802.

It is not a de Polignac number, because 20825709 - 2¹⁷ = 20694637 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 20825709.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20825009) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 41152 + ... + 41654.

It is an arithmetic number, because the mean of its divisors is an integer number (1790712).

Almost surely, 2^20825709 is an apocalyptic number.

It is an amenable number.

20825709 is a deficient number, since it is larger than the sum of its proper divisors (7825683).

20825709 is a wasteful number, since it uses less digits than its factorization.

20825709 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 916.

The product of its (nonzero) digits is 10080, while the sum is 33.

The square root of 20825709 is about 4563.5193655774. The cubic root of 20825709 is about 275.1270333203.

The spelling of 20825709 in words is "twenty million, eight hundred twenty-five thousand, seven hundred nine".