20634143 has 2 divisors, whose sum is σ = 20634144. Its totient is φ = 20634142.

The previous prime is 20634101. The next prime is 20634161. The reversal of 20634143 is 34143602.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20634143 - 2¹⁸ = 20371999 is a prime.

It is equal to p_1308236 and since 20634143 and 1308236 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20634443) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10317071 + 10317072.

It is an arithmetic number, because the mean of its divisors is an integer number (10317072).

Almost surely, 2^20634143 is an apocalyptic number.

20634143 is a deficient number, since it is larger than the sum of its proper divisors (1).

20634143 is an equidigital number, since it uses as much as digits as its factorization.

20634143 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1728, while the sum is 23.

The square root of 20634143 is about 4542.4820307845. The cubic root of 20634143 is about 274.2808449372.

Adding to 20634143 its reverse (34143602), we get a palindrome (54777745).

The spelling of 20634143 in words is "twenty million, six hundred thirty-four thousand, one hundred forty-three".