20285143 has 4 divisors (see below), whose sum is σ = 20486088. Its totient is φ = 20084200.

The previous prime is 20285099. The next prime is 20285263. The reversal of 20285143 is 34158202.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20285143 is a prime.

It is a super-2 number, since 2×20285143² = 822974053060898, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20285443) 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, 100321 + ... + 100522.

It is an arithmetic number, because the mean of its divisors is an integer number (5121522).

Almost surely, 2^20285143 is an apocalyptic number.

20285143 is a deficient number, since it is larger than the sum of its proper divisors (200945).

20285143 is a wasteful number, since it uses less digits than its factorization.

20285143 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 200944.

The product of its (nonzero) digits is 1920, while the sum is 25.

The square root of 20285143 is about 4503.9030851030. The cubic root of 20285143 is about 272.7256745125.

The spelling of 20285143 in words is "twenty million, two hundred eighty-five thousand, one hundred forty-three".