20516147 has 2 divisors, whose sum is σ = 20516148. Its totient is φ = 20516146.

The previous prime is 20516123. The next prime is 20516149. The reversal of 20516147 is 74161502.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20516147 - 2²² = 16321843 is a prime.

Together with 20516149, 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 (20516149) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10258073 + 10258074.

It is an arithmetic number, because the mean of its divisors is an integer number (10258074).

Almost surely, 2^20516147 is an apocalyptic number.

20516147 is a deficient number, since it is larger than the sum of its proper divisors (1).

20516147 is an equidigital number, since it uses as much as digits as its factorization.

20516147 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1680, while the sum is 26.

The square root of 20516147 is about 4529.4753559325. The cubic root of 20516147 is about 273.7570217057.

Adding to 20516147 its reverse (74161502), we get a palindrome (94677649).

The spelling of 20516147 in words is "twenty million, five hundred sixteen thousand, one hundred forty-seven".