20157843 has 8 divisors (see below), whose sum is σ = 27744256. Its totient is φ = 13005000.

The previous prime is 20157833. The next prime is 20157889. The reversal of 20157843 is 34875102.

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

It is not a de Polignac number, because 20157843 - 2⁵ = 20157811 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20157843.

It is not an unprimeable number, because it can be changed into a prime (20157833) 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 7 ways as a sum of consecutive naturals, for example, 108283 + ... + 108468.

It is an arithmetic number, because the mean of its divisors is an integer number (3468032).

Almost surely, 2^20157843 is an apocalyptic number.

20157843 is a deficient number, since it is larger than the sum of its proper divisors (7586413).

20157843 is a wasteful number, since it uses less digits than its factorization.

20157843 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 216785.

The product of its (nonzero) digits is 6720, while the sum is 30.

The square root of 20157843 is about 4489.7486566622. The cubic root of 20157843 is about 272.1539776605.

The spelling of 20157843 in words is "twenty million, one hundred fifty-seven thousand, eight hundred forty-three".