20720573 has 4 divisors (see below), whose sum is σ = 20910780. Its totient is φ = 20530368.

The previous prime is 20720551. The next prime is 20720597. The reversal of 20720573 is 37502702.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 37502702 = 2 ⋅18751351.

It can be written as a sum of positive squares in 2 ways, for example, as 18983449 + 1737124 = 4357^2 + 1318^2 .

It is not a de Polignac number, because 20720573 - 2²⁰ = 19671997 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 (20720533) 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, 94940 + ... + 95157.

It is an arithmetic number, because the mean of its divisors is an integer number (5227695).

Almost surely, 2^20720573 is an apocalyptic number.

It is an amenable number.

20720573 is a deficient number, since it is larger than the sum of its proper divisors (190207).

20720573 is a wasteful number, since it uses less digits than its factorization.

20720573 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 190206.

The product of its (nonzero) digits is 2940, while the sum is 26.

The square root of 20720573 is about 4551.9856106978. The cubic root of 20720573 is about 274.6632704974.

The spelling of 20720573 in words is "twenty million, seven hundred twenty thousand, five hundred seventy-three".