20789709 has 4 divisors (see below), whose sum is σ = 27719616. Its totient is φ = 13859804.

The previous prime is 20789701. The next prime is 20789731. The reversal of 20789709 is 90798702.

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 20789709 - 2³ = 20789701 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20789701) 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, 3464949 + ... + 3464954.

It is an arithmetic number, because the mean of its divisors is an integer number (6929904).

Almost surely, 2^20789709 is an apocalyptic number.

It is an amenable number.

20789709 is a deficient number, since it is larger than the sum of its proper divisors (6929907).

20789709 is an equidigital number, since it uses as much as digits as its factorization.

20789709 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6929906.

The product of its (nonzero) digits is 63504, while the sum is 42.

The square root of 20789709 is about 4559.5733353023. The cubic root of 20789709 is about 274.9684106965.

The spelling of 20789709 in words is "twenty million, seven hundred eighty-nine thousand, seven hundred nine".