10221221987 has 4 divisors (see below), whose sum is σ = 10229649600. Its totient is φ = 10212794376.

The previous prime is 10221221971. The next prime is 10221221993. The reversal of 10221221987 is 78912212201.

10221221987 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 78912212201 = 39251 ⋅2010451.

It is a cyclic number.

It is not a de Polignac number, because 10221221987 - 2⁴ = 10221221971 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (10221221587) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4211987 + ... + 4214412.

It is an arithmetic number, because the mean of its divisors is an integer number (2557412400).

Almost surely, 2^10221221987 is an apocalyptic number.

10221221987 is a deficient number, since it is larger than the sum of its proper divisors (8427613).

10221221987 is an equidigital number, since it uses as much as digits as its factorization.

10221221987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8427612.

The product of its (nonzero) digits is 8064, while the sum is 35.

The spelling of 10221221987 in words is "ten billion, two hundred twenty-one million, two hundred twenty-one thousand, nine hundred eighty-seven".