20355143 has 4 divisors (see below), whose sum is σ = 20905320. Its totient is φ = 19804968.

The previous prime is 20355133. The next prime is 20355149. The reversal of 20355143 is 34155302.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 34155302 = 2 ⋅17077651.

It is a cyclic number.

It is not a de Polignac number, because 20355143 - 2¹⁰ = 20354119 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20355149) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 275033 + ... + 275106.

It is an arithmetic number, because the mean of its divisors is an integer number (5226330).

Almost surely, 2^20355143 is an apocalyptic number.

20355143 is a deficient number, since it is larger than the sum of its proper divisors (550177).

20355143 is an equidigital number, since it uses as much as digits as its factorization.

20355143 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 550176.

The product of its (nonzero) digits is 1800, while the sum is 23.

The square root of 20355143 is about 4511.6674301194. The cubic root of 20355143 is about 273.0390217358.

The spelling of 20355143 in words is "twenty million, three hundred fifty-five thousand, one hundred forty-three".