20540431 has 2 divisors, whose sum is σ = 20540432. Its totient is φ = 20540430.

The previous prime is 20540419. The next prime is 20540441. The reversal of 20540431 is 13404502.

20540431 is nontrivially palindromic in base 15.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20540431 - 2⁹ = 20539919 is a prime.

It is a super-2 number, since 2×20540431² = 843818611331522, which contains 22 as substring.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 20540399 and 20540408.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20540441) 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 as a sum of consecutive naturals, namely, 10270215 + 10270216.

It is an arithmetic number, because the mean of its divisors is an integer number (10270216).

Almost surely, 2^20540431 is an apocalyptic number.

20540431 is a deficient number, since it is larger than the sum of its proper divisors (1).

20540431 is an equidigital number, since it uses as much as digits as its factorization.

20540431 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 480, while the sum is 19.

The square root of 20540431 is about 4532.1552268209. The cubic root of 20540431 is about 273.8649902292.

Adding to 20540431 its reverse (13404502), we get a palindrome (33944933).

The spelling of 20540431 in words is "twenty million, five hundred forty thousand, four hundred thirty-one".