21120201187 has 2 divisors, whose sum is σ = 21120201188. Its totient is φ = 21120201186.

The previous prime is 21120201173. The next prime is 21120201211. The reversal of 21120201187 is 78110202112.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21120201187 - 2¹⁹ = 21119676899 is a prime.

It is not a weakly prime, because it can be changed into another prime (21120211187) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10560100593 + 10560100594.

It is an arithmetic number, because the mean of its divisors is an integer number (10560100594).

Almost surely, 2^21120201187 is an apocalyptic number.

21120201187 is a deficient number, since it is larger than the sum of its proper divisors (1).

21120201187 is an equidigital number, since it uses as much as digits as its factorization.

21120201187 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 448, while the sum is 25.

Adding to 21120201187 its reverse (78110202112), we get a palindrome (99230403299).

The spelling of 21120201187 in words is "twenty-one billion, one hundred twenty million, two hundred one thousand, one hundred eighty-seven".