20780887 has 2 divisors, whose sum is σ = 20780888. Its totient is φ = 20780886.

The previous prime is 20780869. The next prime is 20780941. The reversal of 20780887 is 78808702.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20780887 - 2⁷ = 20780759 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20780807) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10390443 + 10390444.

It is an arithmetic number, because the mean of its divisors is an integer number (10390444).

Almost surely, 2^20780887 is an apocalyptic number.

20780887 is a deficient number, since it is larger than the sum of its proper divisors (1).

20780887 is an equidigital number, since it uses as much as digits as its factorization.

20780887 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 50176, while the sum is 40.

The square root of 20780887 is about 4558.6058175719. The cubic root of 20780887 is about 274.9295114103.

The spelling of 20780887 in words is "twenty million, seven hundred eighty thousand, eight hundred eighty-seven".