21210284089 has 2 divisors, whose sum is σ = 21210284090. Its totient is φ = 21210284088.

The previous prime is 21210284083. The next prime is 21210284093. The reversal of 21210284089 is 98048201212.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12321000000 + 8889284089 = 111000^2 + 94283^2 .

It is a cyclic number.

It is not a de Polignac number, because 21210284089 - 2¹⁹ = 21209759801 is a prime.

It is a super-2 number, since 2×21210284089² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21210284083) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10605142044 + 10605142045.

It is an arithmetic number, because the mean of its divisors is an integer number (10605142045).

Almost surely, 2^21210284089 is an apocalyptic number.

It is an amenable number.

21210284089 is a deficient number, since it is larger than the sum of its proper divisors (1).

21210284089 is an equidigital number, since it uses as much as digits as its factorization.

21210284089 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 18432, while the sum is 37.

The spelling of 21210284089 in words is "twenty-one billion, two hundred ten million, two hundred eighty-four thousand, eighty-nine".