20820673 has 4 divisors (see below), whose sum is σ = 20845188. Its totient is φ = 20796160.

The previous prime is 20820649. The next prime is 20820689. The reversal of 20820673 is 37602802.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 37602802 = 2 ⋅18801401.

It can be written as a sum of positive squares in 2 ways, for example, as 11778624 + 9042049 = 3432^2 + 3007^2 .

It is a cyclic number.

It is not a de Polignac number, because 20820673 - 2⁹ = 20820161 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20820073) 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, 10936 + ... + 12697.

It is an arithmetic number, because the mean of its divisors is an integer number (5211297).

Almost surely, 2^20820673 is an apocalyptic number.

It is an amenable number.

20820673 is a deficient number, since it is larger than the sum of its proper divisors (24515).

20820673 is an equidigital number, since it uses as much as digits as its factorization.

20820673 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24514.

The product of its (nonzero) digits is 4032, while the sum is 28.

The square root of 20820673 is about 4562.9675650831. The cubic root of 20820673 is about 275.1048547807.

The spelling of 20820673 in words is "twenty million, eight hundred twenty thousand, six hundred seventy-three".