20816605087 has 2 divisors, whose sum is σ = 20816605088. Its totient is φ = 20816605086.

The previous prime is 20816605079. The next prime is 20816605099. The reversal of 20816605087 is 78050661802.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20816605087 - 2³ = 20816605079 is a prime.

It is a super-2 number, since 2×20816605087² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20816605787) 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, 10408302543 + 10408302544.

It is an arithmetic number, because the mean of its divisors is an integer number (10408302544).

Almost surely, 2^20816605087 is an apocalyptic number.

20816605087 is a deficient number, since it is larger than the sum of its proper divisors (1).

20816605087 is an equidigital number, since it uses as much as digits as its factorization.

20816605087 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 161280, while the sum is 43.

The spelling of 20816605087 in words is "twenty billion, eight hundred sixteen million, six hundred five thousand, eighty-seven".