21130110251 has 2 divisors, whose sum is σ = 21130110252. Its totient is φ = 21130110250.

The previous prime is 21130110247. The next prime is 21130110283. The reversal of 21130110251 is 15201103112.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21130110251 - 2² = 21130110247 is a prime.

It is not a weakly prime, because it can be changed into another prime (21130110451) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10565055125 + 10565055126.

It is an arithmetic number, because the mean of its divisors is an integer number (10565055126).

Almost surely, 2^21130110251 is an apocalyptic number.

21130110251 is a deficient number, since it is larger than the sum of its proper divisors (1).

21130110251 is an equidigital number, since it uses as much as digits as its factorization.

21130110251 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 60, while the sum is 17.

Adding to 21130110251 its reverse (15201103112), we get a palindrome (36331213363).

The spelling of 21130110251 in words is "twenty-one billion, one hundred thirty million, one hundred ten thousand, two hundred fifty-one".