20317409 has 6 divisors (see below), whose sum is σ = 23634594. Its totient is φ = 17414880.

The previous prime is 20317379. The next prime is 20317411. The reversal of 20317409 is 90471302.

It can be written as a sum of positive squares in only one way, i.e., 20070400 + 247009 = 4480^2 + 497^2 .

It is a de Polignac number, because none of the positive numbers 2^k-20317409 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20317439) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 207272 + ... + 207369.

It is an arithmetic number, because the mean of its divisors is an integer number (3939099).

Almost surely, 2^20317409 is an apocalyptic number.

It is an amenable number.

20317409 is a deficient number, since it is larger than the sum of its proper divisors (3317185).

20317409 is an equidigital number, since it uses as much as digits as its factorization.

20317409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 414655 (or 414648 counting only the distinct ones).

The product of its (nonzero) digits is 1512, while the sum is 26.

The square root of 20317409 is about 4507.4836660824. The cubic root of 20317409 is about 272.8701990878.

The spelling of 20317409 in words is "twenty million, three hundred seventeen thousand, four hundred nine".