20557843 has 8 divisors (see below), whose sum is σ = 21003840. Its totient is φ = 20116800.

The previous prime is 20557819. The next prime is 20557853. The reversal of 20557843 is 34875502.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20557843 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20557799 and 20557808.

It is not an unprimeable number, because it can be changed into a prime (20557813) 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 7 ways as a sum of consecutive naturals, for example, 7846 + ... + 10132.

It is an arithmetic number, because the mean of its divisors is an integer number (2625480).

Almost surely, 2^20557843 is an apocalyptic number.

20557843 is a deficient number, since it is larger than the sum of its proper divisors (445997).

20557843 is a wasteful number, since it uses less digits than its factorization.

20557843 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2477.

The product of its (nonzero) digits is 33600, while the sum is 34.

The square root of 20557843 is about 4534.0757602846. The cubic root of 20557843 is about 273.9423529425.

The spelling of 20557843 in words is "twenty million, five hundred fifty-seven thousand, eight hundred forty-three".