20709573 has 4 divisors (see below), whose sum is σ = 27612768. Its totient is φ = 13806380.

The previous prime is 20709571. The next prime is 20709583. The reversal of 20709573 is 37590702.

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 20709573 - 2¹ = 20709571 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20709571) 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, 3451593 + ... + 3451598.

It is an arithmetic number, because the mean of its divisors is an integer number (6903192).

Almost surely, 2^20709573 is an apocalyptic number.

It is an amenable number.

20709573 is a deficient number, since it is larger than the sum of its proper divisors (6903195).

20709573 is an equidigital number, since it uses as much as digits as its factorization.

20709573 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6903194.

The product of its (nonzero) digits is 13230, while the sum is 33.

The square root of 20709573 is about 4550.7771863716. Note that the first 3 decimals coincide. The cubic root of 20709573 is about 274.6146580906.

The spelling of 20709573 in words is "twenty million, seven hundred nine thousand, five hundred seventy-three".