21008000873 has 2 divisors, whose sum is σ = 21008000874. Its totient is φ = 21008000872.

The previous prime is 21008000861. The next prime is 21008000879. The reversal of 21008000873 is 37800080012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16444728169 + 4563272704 = 128237^2 + 67552^2 .

It is a cyclic number.

It is not a de Polignac number, because 21008000873 - 2²² = 21003806569 is a prime.

It is a super-2 number, since 2×21008000873² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21008000879) 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, 10504000436 + 10504000437.

It is an arithmetic number, because the mean of its divisors is an integer number (10504000437).

Almost surely, 2^21008000873 is an apocalyptic number.

It is an amenable number.

21008000873 is a deficient number, since it is larger than the sum of its proper divisors (1).

21008000873 is an equidigital number, since it uses as much as digits as its factorization.

21008000873 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2688, while the sum is 29.

Adding to 21008000873 its reverse (37800080012), we get a palindrome (58808080885).

The spelling of 21008000873 in words is "twenty-one billion, eight million, eight hundred seventy-three", and thus it is an aban number.