20508973 has 4 divisors (see below), whose sum is σ = 20555100. Its totient is φ = 20462848.

The previous prime is 20508941. The next prime is 20508991. The reversal of 20508973 is 37980502.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 15856324 + 4652649 = 3982^2 + 2157^2 .

It is a cyclic number.

It is not a de Polignac number, because 20508973 - 2⁵ = 20508941 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 (20508913) 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 3 ways as a sum of consecutive naturals, for example, 22390 + ... + 23287.

It is an arithmetic number, because the mean of its divisors is an integer number (5138775).

Almost surely, 2^20508973 is an apocalyptic number.

It is an amenable number.

20508973 is a deficient number, since it is larger than the sum of its proper divisors (46127).

20508973 is an equidigital number, since it uses as much as digits as its factorization.

20508973 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 46126.

The product of its (nonzero) digits is 15120, while the sum is 34.

The square root of 20508973 is about 4528.6833627446. The cubic root of 20508973 is about 273.7251092511.

The spelling of 20508973 in words is "twenty million, five hundred eight thousand, nine hundred seventy-three".