20819173 has 2 divisors, whose sum is σ = 20819174. Its totient is φ = 20819172.

The previous prime is 20819143. The next prime is 20819213. The reversal of 20819173 is 37191802.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13300609 + 7518564 = 3647^2 + 2742^2 .

It is a cyclic number.

It is not a de Polignac number, because 20819173 - 2¹³ = 20810981 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20819143) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10409586 + 10409587.

It is an arithmetic number, because the mean of its divisors is an integer number (10409587).

Almost surely, 2^20819173 is an apocalyptic number.

It is an amenable number.

20819173 is a deficient number, since it is larger than the sum of its proper divisors (1).

20819173 is an equidigital number, since it uses as much as digits as its factorization.

20819173 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3024, while the sum is 31.

The square root of 20819173 is about 4562.8031954052. The cubic root of 20819173 is about 275.0982480907.

The spelling of 20819173 in words is "twenty million, eight hundred nineteen thousand, one hundred seventy-three".