21212000987 has 2 divisors, whose sum is σ = 21212000988. Its totient is φ = 21212000986.

The previous prime is 21212000977. The next prime is 21212001029. The reversal of 21212000987 is 78900021212.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21212000987 - 2⁸ = 21212000731 is a prime.

It is not a weakly prime, because it can be changed into another prime (21212000977) 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, 10606000493 + 10606000494.

It is an arithmetic number, because the mean of its divisors is an integer number (10606000494).

Almost surely, 2^21212000987 is an apocalyptic number.

21212000987 is a deficient number, since it is larger than the sum of its proper divisors (1).

21212000987 is an equidigital number, since it uses as much as digits as its factorization.

21212000987 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4032, while the sum is 32.

The spelling of 21212000987 in words is "twenty-one billion, two hundred twelve million, nine hundred eighty-seven", and thus it is an aban number.