20543131 has 4 divisors (see below), whose sum is σ = 23477872. Its totient is φ = 17608392.

The previous prime is 20543119. The next prime is 20543137. The reversal of 20543131 is 13134502.

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 20543131 - 2¹³ = 20534939 is a prime.

It is a super-2 number, since 2×20543131² = 844040462566322, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20543099 and 20543108.

It is not an unprimeable number, because it can be changed into a prime (20543137) 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, 1467360 + ... + 1467373.

It is an arithmetic number, because the mean of its divisors is an integer number (5869468).

Almost surely, 2^20543131 is an apocalyptic number.

20543131 is a deficient number, since it is larger than the sum of its proper divisors (2934741).

20543131 is an equidigital number, since it uses as much as digits as its factorization.

20543131 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2934740.

The product of its (nonzero) digits is 360, while the sum is 19.

The square root of 20543131 is about 4532.4530885603. The cubic root of 20543131 is about 273.8769893782.

Adding to 20543131 its reverse (13134502), we get a palindrome (33677633).

The spelling of 20543131 in words is "twenty million, five hundred forty-three thousand, one hundred thirty-one".