20872147 has 2 divisors, whose sum is σ = 20872148. Its totient is φ = 20872146.

The previous prime is 20872139. The next prime is 20872151. The reversal of 20872147 is 74127802.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20872147 - 2³ = 20872139 is a prime.

It is not a weakly prime, because it can be changed into another prime (20812147) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10436073 + 10436074.

It is an arithmetic number, because the mean of its divisors is an integer number (10436074).

Almost surely, 2^20872147 is an apocalyptic number.

20872147 is a deficient number, since it is larger than the sum of its proper divisors (1).

20872147 is an equidigital number, since it uses as much as digits as its factorization.

20872147 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6272, while the sum is 31.

The square root of 20872147 is about 4568.6044915269. The cubic root of 20872147 is about 275.3313779361.

Adding to 20872147 its reverse (74127802), we get a palindrome (94999949).

The spelling of 20872147 in words is "twenty million, eight hundred seventy-two thousand, one hundred forty-seven".