21102201187 has 2 divisors, whose sum is σ = 21102201188. Its totient is φ = 21102201186.

The previous prime is 21102201181. The next prime is 21102201217. The reversal of 21102201187 is 78110220112.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21102201187 - 2³ = 21102201179 is a prime.

It is not a weakly prime, because it can be changed into another prime (21102201181) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10551100593 + 10551100594.

It is an arithmetic number, because the mean of its divisors is an integer number (10551100594).

Almost surely, 2^21102201187 is an apocalyptic number.

21102201187 is a deficient number, since it is larger than the sum of its proper divisors (1).

21102201187 is an equidigital number, since it uses as much as digits as its factorization.

21102201187 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 21102201187 its reverse (78110220112), we get a palindrome (99212421299).

The spelling of 21102201187 in words is "twenty-one billion, one hundred two million, two hundred one thousand, one hundred eighty-seven".