20847887 has 2 divisors, whose sum is σ = 20847888. Its totient is φ = 20847886.

The previous prime is 20847881. The next prime is 20847889. The reversal of 20847887 is 78874802.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20847887 - 2¹⁶ = 20782351 is a prime.

Together with 20847889, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20847881) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10423943 + 10423944.

It is an arithmetic number, because the mean of its divisors is an integer number (10423944).

Almost surely, 2^20847887 is an apocalyptic number.

20847887 is a deficient number, since it is larger than the sum of its proper divisors (1).

20847887 is an equidigital number, since it uses as much as digits as its factorization.

20847887 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 200704, while the sum is 44.

The square root of 20847887 is about 4565.9486418487. The cubic root of 20847887 is about 275.2246626916.

The spelling of 20847887 in words is "twenty million, eight hundred forty-seven thousand, eight hundred eighty-seven".