20819893 has 2 divisors, whose sum is σ = 20819894. Its totient is φ = 20819892.

The previous prime is 20819867. The next prime is 20819921. The reversal of 20819893 is 39891802.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11437924 + 9381969 = 3382^2 + 3063^2 .

It is a cyclic number.

It is not a de Polignac number, because 20819893 - 2²¹ = 18722741 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20819093) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10409946 + 10409947.

It is an arithmetic number, because the mean of its divisors is an integer number (10409947).

Almost surely, 2^20819893 is an apocalyptic number.

It is an amenable number.

20819893 is a deficient number, since it is larger than the sum of its proper divisors (1).

20819893 is an equidigital number, since it uses as much as digits as its factorization.

20819893 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 31104, while the sum is 40.

The square root of 20819893 is about 4562.8820935895. The cubic root of 20819893 is about 275.1014193415.

It can be divided in two parts, 20819 and 893, that added together give a palindrome (21712).

The spelling of 20819893 in words is "twenty million, eight hundred nineteen thousand, eight hundred ninety-three".