20807789 has 4 divisors (see below), whose sum is σ = 21479040. Its totient is φ = 20136540.

The previous prime is 20807753. The next prime is 20807791. The reversal of 20807789 is 98770802.

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 20807789 - 2⁸ = 20807533 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20807749) 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, 335579 + ... + 335640.

It is an arithmetic number, because the mean of its divisors is an integer number (5369760).

Almost surely, 2^20807789 is an apocalyptic number.

It is an amenable number.

20807789 is a deficient number, since it is larger than the sum of its proper divisors (671251).

20807789 is an equidigital number, since it uses as much as digits as its factorization.

20807789 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 671250.

The product of its (nonzero) digits is 56448, while the sum is 41.

The square root of 20807789 is about 4561.5555460829. Note that the first 4 decimals coincide. The cubic root of 20807789 is about 275.0480973724.

The spelling of 20807789 in words is "twenty million, eight hundred seven thousand, seven hundred eighty-nine".