20117431 has 2 divisors, whose sum is σ = 20117432. Its totient is φ = 20117430.

The previous prime is 20117411. The next prime is 20117437. The reversal of 20117431 is 13471102.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20117431 - 2⁷ = 20117303 is a prime.

It is a super-2 number, since 2×20117431² = 809422060079522, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 20117399 and 20117408.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20117437) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10058715 + 10058716.

It is an arithmetic number, because the mean of its divisors is an integer number (10058716).

Almost surely, 2^20117431 is an apocalyptic number.

20117431 is a deficient number, since it is larger than the sum of its proper divisors (1).

20117431 is an equidigital number, since it uses as much as digits as its factorization.

20117431 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 168, while the sum is 19.

The square root of 20117431 is about 4485.2459241384. The cubic root of 20117431 is about 271.9719865541.

Adding to 20117431 its reverse (13471102), we get a palindrome (33588533).

The spelling of 20117431 in words is "twenty million, one hundred seventeen thousand, four hundred thirty-one".