20431243 has 16 divisors (see below), whose sum is σ = 24099264. Its totient is φ = 16957440.

The previous prime is 20431237. The next prime is 20431247. The reversal of 20431243 is 34213402.

It is a cyclic number.

It is not a de Polignac number, because 20431243 - 2⁵ = 20431211 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20431243.

It is not an unprimeable number, because it can be changed into a prime (20431247) 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 15 ways as a sum of consecutive naturals, for example, 73621 + ... + 73897.

It is an arithmetic number, because the mean of its divisors is an integer number (1506204).

Almost surely, 2^20431243 is an apocalyptic number.

20431243 is a deficient number, since it is larger than the sum of its proper divisors (3668021).

20431243 is a wasteful number, since it uses less digits than its factorization.

20431243 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 582.

The product of its (nonzero) digits is 576, while the sum is 19.

The square root of 20431243 is about 4520.0932512505. The cubic root of 20431243 is about 273.3788609800.

Adding to 20431243 its reverse (34213402), we get a palindrome (54644645).

The spelling of 20431243 in words is "twenty million, four hundred thirty-one thousand, two hundred forty-three".