20752809 has 16 divisors (see below), whose sum is σ = 34498560. Its totient is φ = 10780560.

The previous prime is 20752799. The next prime is 20752811. The reversal of 20752809 is 90825702.

It is not a de Polignac number, because 20752809 - 2⁷ = 20752681 is a prime.

It is a super-3 number, since 3×20752809³ (a number of 23 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a self number, because there is not a number n which added to its sum of digits gives 20752809.

It is not an unprimeable number, because it can be changed into a prime (20752829) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 44689 + ... + 45150.

It is an arithmetic number, because the mean of its divisors is an integer number (2156160).

Almost surely, 2^20752809 is an apocalyptic number.

It is an amenable number.

20752809 is a deficient number, since it is larger than the sum of its proper divisors (13745751).

20752809 is a wasteful number, since it uses less digits than its factorization.

20752809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 89860.

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

The square root of 20752809 is about 4555.5251069443. The cubic root of 20752809 is about 274.8056323519.

It can be divided in two parts, 2075 and 2809, that added together give a palindrome (4884).

The spelling of 20752809 in words is "twenty million, seven hundred fifty-two thousand, eight hundred nine".