20843859 has 4 divisors (see below), whose sum is σ = 27791816. Its totient is φ = 13895904.

The previous prime is 20843843. The next prime is 20843861. The reversal of 20843859 is 95834802.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 20843859 - 2⁴ = 20843843 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20843869) 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, 3473974 + ... + 3473979.

It is an arithmetic number, because the mean of its divisors is an integer number (6947954).

Almost surely, 2^20843859 is an apocalyptic number.

20843859 is a deficient number, since it is larger than the sum of its proper divisors (6947957).

20843859 is an equidigital number, since it uses as much as digits as its factorization.

20843859 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6947956.

The product of its (nonzero) digits is 69120, while the sum is 39.

The square root of 20843859 is about 4565.5075292896. The cubic root of 20843859 is about 275.2069362534.

The spelling of 20843859 in words is "twenty million, eight hundred forty-three thousand, eight hundred fifty-nine".