20320217431 has 2 divisors, whose sum is σ = 20320217432. Its totient is φ = 20320217430.

The previous prime is 20320217387. The next prime is 20320217473. The reversal of 20320217431 is 13471202302.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20320217431 - 2¹⁵ = 20320184663 is a prime.

It is a super-2 number, since 2×20320217431² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 20320217396 and 20320217405.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20320217231) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10160108715 + 10160108716.

It is an arithmetic number, because the mean of its divisors is an integer number (10160108716).

Almost surely, 2^20320217431 is an apocalyptic number.

20320217431 is a deficient number, since it is larger than the sum of its proper divisors (1).

20320217431 is an equidigital number, since it uses as much as digits as its factorization.

20320217431 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2016, while the sum is 25.

Adding to 20320217431 its reverse (13471202302), we get a palindrome (33791419733).

The spelling of 20320217431 in words is "twenty billion, three hundred twenty million, two hundred seventeen thousand, four hundred thirty-one".