20631173 has 2 divisors, whose sum is σ = 20631174. Its totient is φ = 20631172.

The previous prime is 20631157. The next prime is 20631203. The reversal of 20631173 is 37113602.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17123044 + 3508129 = 4138^2 + 1873^2 .

It is a cyclic number.

It is not a de Polignac number, because 20631173 - 2⁴ = 20631157 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20631103) 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, 10315586 + 10315587.

It is an arithmetic number, because the mean of its divisors is an integer number (10315587).

Almost surely, 2^20631173 is an apocalyptic number.

It is an amenable number.

20631173 is a deficient number, since it is larger than the sum of its proper divisors (1).

20631173 is an equidigital number, since it uses as much as digits as its factorization.

20631173 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 756, while the sum is 23.

The square root of 20631173 is about 4542.1551052336. The cubic root of 20631173 is about 274.2676846589.

Adding to 20631173 its reverse (37113602), we get a palindrome (57744775).

The spelling of 20631173 in words is "twenty million, six hundred thirty-one thousand, one hundred seventy-three".