21221030287 has 2 divisors, whose sum is σ = 21221030288. Its totient is φ = 21221030286.

The previous prime is 21221030269. The next prime is 21221030371. The reversal of 21221030287 is 78203012212.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21221030287 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21221030267) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10610515143 + 10610515144.

It is an arithmetic number, because the mean of its divisors is an integer number (10610515144).

Almost surely, 2^21221030287 is an apocalyptic number.

21221030287 is a deficient number, since it is larger than the sum of its proper divisors (1).

21221030287 is an equidigital number, since it uses as much as digits as its factorization.

21221030287 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 28.

Adding to 21221030287 its reverse (78203012212), we get a palindrome (99424042499).

The spelling of 21221030287 in words is "twenty-one billion, two hundred twenty-one million, thirty thousand, two hundred eighty-seven".