21210030187 has 2 divisors, whose sum is σ = 21210030188. Its totient is φ = 21210030186.

The previous prime is 21210030181. The next prime is 21210030253. The reversal of 21210030187 is 78103001212.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21210030187 - 2¹¹ = 21210028139 is a prime.

It is not a weakly prime, because it can be changed into another prime (21210030181) 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 as a sum of consecutive naturals, namely, 10605015093 + 10605015094.

It is an arithmetic number, because the mean of its divisors is an integer number (10605015094).

Almost surely, 2^21210030187 is an apocalyptic number.

21210030187 is a deficient number, since it is larger than the sum of its proper divisors (1).

21210030187 is an equidigital number, since it uses as much as digits as its factorization.

21210030187 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 672, while the sum is 25.

Adding to 21210030187 its reverse (78103001212), we get a palindrome (99313031399).

The spelling of 21210030187 in words is "twenty-one billion, two hundred ten million, thirty thousand, one hundred eighty-seven".