20516047 has 2 divisors, whose sum is σ = 20516048. Its totient is φ = 20516046.

The previous prime is 20516039. The next prime is 20516057. The reversal of 20516047 is 74061502.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20516047 - 2³ = 20516039 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20516057) 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, 10258023 + 10258024.

It is an arithmetic number, because the mean of its divisors is an integer number (10258024).

Almost surely, 2^20516047 is an apocalyptic number.

20516047 is a deficient number, since it is larger than the sum of its proper divisors (1).

20516047 is an equidigital number, since it uses as much as digits as its factorization.

20516047 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1680, while the sum is 25.

The square root of 20516047 is about 4529.4643171130. The cubic root of 20516047 is about 273.7565769220.

Adding to 20516047 its reverse (74061502), we get a palindrome (94577549).

The spelling of 20516047 in words is "twenty million, five hundred sixteen thousand, forty-seven".