20642177 has 2 divisors, whose sum is σ = 20642178. Its totient is φ = 20642176.

The previous prime is 20642173. The next prime is 20642179. The reversal of 20642177 is 77124602.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16248961 + 4393216 = 4031^2 + 2096^2 .

It is a cyclic number.

It is not a de Polignac number, because 20642177 - 2² = 20642173 is a prime.

Together with 20642179, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (20642173) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10321088 + 10321089.

It is an arithmetic number, because the mean of its divisors is an integer number (10321089).

Almost surely, 2^20642177 is an apocalyptic number.

It is an amenable number.

20642177 is a deficient number, since it is larger than the sum of its proper divisors (1).

20642177 is an equidigital number, since it uses as much as digits as its factorization.

20642177 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4704, while the sum is 29.

The square root of 20642177 is about 4543.3662630257. The cubic root of 20642177 is about 274.3164378278.

Adding to 20642177 its reverse (77124602), we get a palindrome (97766779).

The spelling of 20642177 in words is "twenty million, six hundred forty-two thousand, one hundred seventy-seven".