21201221110987 has 2 divisors, whose sum is σ = 21201221110988. Its totient is φ = 21201221110986.

The previous prime is 21201221110967. The next prime is 21201221111029. The reversal of 21201221110987 is 78901112210212.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21201221110987 is a prime.

It is a super-2 number, since 2×21201221110987² (a number of 27 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21201221110907) 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, 10600610555493 + 10600610555494.

It is an arithmetic number, because the mean of its divisors is an integer number (10600610555494).

Almost surely, 2^{21201221110987} is an apocalyptic number.

21201221110987 is a deficient number, since it is larger than the sum of its proper divisors (1).

21201221110987 is an equidigital number, since it uses as much as digits as its factorization.

21201221110987 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8064, while the sum is 37.

The spelling of 21201221110987 in words is "twenty-one trillion, two hundred one billion, two hundred twenty-one million, one hundred ten thousand, nine hundred eighty-seven".