20172797 has 2 divisors, whose sum is σ = 20172798. Its totient is φ = 20172796.

The previous prime is 20172781. The next prime is 20172827. The reversal of 20172797 is 79727102.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17397241 + 2775556 = 4171^2 + 1666^2 .

It is a cyclic number.

It is not a de Polignac number, because 20172797 - 2⁴ = 20172781 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20172707) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10086398 + 10086399.

It is an arithmetic number, because the mean of its divisors is an integer number (10086399).

Almost surely, 2^20172797 is an apocalyptic number.

It is an amenable number.

20172797 is a deficient number, since it is larger than the sum of its proper divisors (1).

20172797 is an equidigital number, since it uses as much as digits as its factorization.

20172797 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 12348, while the sum is 35.

The square root of 20172797 is about 4491.4136972673. The cubic root of 20172797 is about 272.2212597371.

Adding to 20172797 its reverse (79727102), we get a palindrome (99899899).

The spelling of 20172797 in words is "twenty million, one hundred seventy-two thousand, seven hundred ninety-seven".