20317997 has 6 divisors (see below), whose sum is σ = 23635278. Its totient is φ = 17415384.

The previous prime is 20317991. The next prime is 20318003. The reversal of 20317997 is 79971302.

It is an interprime number because it is at equal distance from previous prime (20317991) and next prime (20318003).

It can be written as a sum of positive squares in only one way, i.e., 11383876 + 8934121 = 3374^2 + 2989^2 .

It is not a de Polignac number, because 20317997 - 2⁴ = 20317981 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20317997.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20317991) 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, 207278 + ... + 207375.

It is an arithmetic number, because the mean of its divisors is an integer number (3939213).

Almost surely, 2^20317997 is an apocalyptic number.

It is an amenable number.

20317997 is a deficient number, since it is larger than the sum of its proper divisors (3317281).

20317997 is an equidigital number, since it uses as much as digits as its factorization.

20317997 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 414667 (or 414660 counting only the distinct ones).

The product of its (nonzero) digits is 23814, while the sum is 38.

The square root of 20317997 is about 4507.5488904725. The cubic root of 20317997 is about 272.8728314138.

The spelling of 20317997 in words is "twenty million, three hundred seventeen thousand, nine hundred ninety-seven".