20431317 has 8 divisors (see below), whose sum is σ = 27292896. Its totient is φ = 13595312.

The previous prime is 20431309. The next prime is 20431319. The reversal of 20431317 is 71313402.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20431317 - 2³ = 20431309 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20431293 and 20431302.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20431319) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4443 + ... + 7784.

It is an arithmetic number, because the mean of its divisors is an integer number (3411612).

Almost surely, 2^20431317 is an apocalyptic number.

It is an amenable number.

20431317 is a deficient number, since it is larger than the sum of its proper divisors (6861579).

20431317 is a wasteful number, since it uses less digits than its factorization.

20431317 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12787.

The product of its (nonzero) digits is 504, while the sum is 21.

The square root of 20431317 is about 4520.1014369149. The cubic root of 20431317 is about 273.3791910302.

Adding to 20431317 its reverse (71313402), we get a palindrome (91744719).

The spelling of 20431317 in words is "twenty million, four hundred thirty-one thousand, three hundred seventeen".