21102010123 has 16 divisors (see below), whose sum is σ = 22088871936. Its totient is φ = 20121060960.

The previous prime is 21102010117. The next prime is 21102010141. The reversal of 21102010123 is 32101020112.

It is a cyclic number.

It is not a de Polignac number, because 21102010123 - 2⁵ = 21102010091 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21102010823) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 17253690 + ... + 17254912.

It is an arithmetic number, because the mean of its divisors is an integer number (1380554496).

Almost surely, 2^21102010123 is an apocalyptic number.

21102010123 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

21102010123 is a deficient number, since it is larger than the sum of its proper divisors (986861813).

21102010123 is a wasteful number, since it uses less digits than its factorization.

21102010123 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2994.

The product of its (nonzero) digits is 24, while the sum is 13.

Adding to 21102010123 its reverse (32101020112), we get a palindrome (53203030235).

The spelling of 21102010123 in words is "twenty-one billion, one hundred two million, ten thousand, one hundred twenty-three".