20870887 has 2 divisors, whose sum is σ = 20870888. Its totient is φ = 20870886.

The previous prime is 20870881. The next prime is 20870909. The reversal of 20870887 is 78807802.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20870887 - 2³ = 20870879 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20870881) 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, 10435443 + 10435444.

It is an arithmetic number, because the mean of its divisors is an integer number (10435444).

Almost surely, 2^20870887 is an apocalyptic number.

20870887 is a deficient number, since it is larger than the sum of its proper divisors (1).

20870887 is an equidigital number, since it uses as much as digits as its factorization.

20870887 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 20870887 is about 4568.4665917570. The cubic root of 20870887 is about 275.3258374661.

The spelling of 20870887 in words is "twenty million, eight hundred seventy thousand, eight hundred eighty-seven".