21221011100987 has 2 divisors, whose sum is σ = 21221011100988. Its totient is φ = 21221011100986.

The previous prime is 21221011100899. The next prime is 21221011101023. The reversal of 21221011100987 is 78900111012212.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21221011100987 - 2²⁶ = 21220943992123 is a prime.

It is not a weakly prime, because it can be changed into another prime (21221011100587) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10610505550493 + 10610505550494.

It is an arithmetic number, because the mean of its divisors is an integer number (10610505550494).

Almost surely, 2^{21221011100987} is an apocalyptic number.

21221011100987 is a deficient number, since it is larger than the sum of its proper divisors (1).

21221011100987 is an equidigital number, since it uses as much as digits as its factorization.

21221011100987 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 35.

The spelling of 21221011100987 in words is "twenty-one trillion, two hundred twenty-one billion, eleven million, one hundred thousand, nine hundred eighty-seven".