20887547 has 2 divisors, whose sum is σ = 20887548. Its totient is φ = 20887546.

The previous prime is 20887541. The next prime is 20887549. The reversal of 20887547 is 74578802.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20887547 - 2⁶ = 20887483 is a prime.

Together with 20887549, 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 (20887541) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10443773 + 10443774.

It is an arithmetic number, because the mean of its divisors is an integer number (10443774).

Almost surely, 2^20887547 is an apocalyptic number.

20887547 is a deficient number, since it is larger than the sum of its proper divisors (1).

20887547 is an equidigital number, since it uses as much as digits as its factorization.

20887547 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 125440, while the sum is 41.

The square root of 20887547 is about 4570.2895969512. The cubic root of 20887547 is about 275.3990767826.

The spelling of 20887547 in words is "twenty million, eight hundred eighty-seven thousand, five hundred forty-seven".