20843057 has 6 divisors (see below), whose sum is σ = 21998178. Its totient is φ = 19745712.

The previous prime is 20843051. The next prime is 20843087. The reversal of 20843057 is 75034802.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 13868176 + 6974881 = 3724^2 + 2641^2 .

It is a de Polignac number, because none of the positive numbers 2^k-20843057 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20843051) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 28508 + ... + 29229.

It is an arithmetic number, because the mean of its divisors is an integer number (3666363).

Almost surely, 2^20843057 is an apocalyptic number.

It is an amenable number.

20843057 is a deficient number, since it is larger than the sum of its proper divisors (1155121).

20843057 is an equidigital number, since it uses as much as digits as its factorization.

20843057 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57775 (or 57756 counting only the distinct ones).

The product of its (nonzero) digits is 6720, while the sum is 29.

The square root of 20843057 is about 4565.4196959316. The cubic root of 20843057 is about 275.2034065360.

Adding to 20843057 its reverse (75034802), we get a palindrome (95877859).

The spelling of 20843057 in words is "twenty million, eight hundred forty-three thousand, fifty-seven".