21100010123 has 2 divisors, whose sum is σ = 21100010124. Its totient is φ = 21100010122.

The previous prime is 21100010119. The next prime is 21100010137. The reversal of 21100010123 is 32101000112.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21100010123 - 2² = 21100010119 is a prime.

It is not a weakly prime, because it can be changed into another prime (21100010423) 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, 10550005061 + 10550005062.

It is an arithmetic number, because the mean of its divisors is an integer number (10550005062).

Almost surely, 2^21100010123 is an apocalyptic number.

21100010123 is a deficient number, since it is larger than the sum of its proper divisors (1).

21100010123 is an equidigital number, since it uses as much as digits as its factorization.

21100010123 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 12, while the sum is 11.

Adding to 21100010123 its reverse (32101000112), we get a palindrome (53201010235).

The spelling of 21100010123 in words is "twenty-one billion, one hundred million, ten thousand, one hundred twenty-three".