21008000851 has 2 divisors, whose sum is σ = 21008000852. Its totient is φ = 21008000850.

The previous prime is 21008000831. The next prime is 21008000861. The reversal of 21008000851 is 15800080012.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21008000851 - 2¹⁵ = 21007968083 is a prime.

It is a super-3 number, since 3×21008000851³ (a number of 32 digits) contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (21008000831) 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, 10504000425 + 10504000426.

It is an arithmetic number, because the mean of its divisors is an integer number (10504000426).

Almost surely, 2^21008000851 is an apocalyptic number.

21008000851 is a deficient number, since it is larger than the sum of its proper divisors (1).

21008000851 is an equidigital number, since it uses as much as digits as its factorization.

21008000851 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 640, while the sum is 25.

Adding to 21008000851 its reverse (15800080012), we get a palindrome (36808080863).

The spelling of 21008000851 in words is "twenty-one billion, eight million, eight hundred fifty-one", and thus it is an aban number.