20543231 has 4 divisors (see below), whose sum is σ = 20662152. Its totient is φ = 20424312.

The previous prime is 20543221. The next prime is 20543233. The reversal of 20543231 is 13234502.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 20543231 - 2⁶ = 20543167 is a prime.

It is a super-2 number, since 2×20543231² = 844048679838722, 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 (20543233) 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, 59201 + ... + 59546.

It is an arithmetic number, because the mean of its divisors is an integer number (5165538).

Almost surely, 2^20543231 is an apocalyptic number.

20543231 is a deficient number, since it is larger than the sum of its proper divisors (118921).

20543231 is a wasteful number, since it uses less digits than its factorization.

20543231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 118920.

The product of its (nonzero) digits is 720, while the sum is 20.

The square root of 20543231 is about 4532.4641201007. The cubic root of 20543231 is about 273.8774337709.

Adding to 20543231 its reverse (13234502), we get a palindrome (33777733).

The spelling of 20543231 in words is "twenty million, five hundred forty-three thousand, two hundred thirty-one".