21000123110 has 32 divisors (see below), whose sum is σ = 39258846720. Its totient is φ = 8081969632.

The previous prime is 21000123101. The next prime is 21000123127. The reversal of 21000123110 is 1132100012.

It is a junction number, because it is equal to n+sod(n) for n = 21000123091 and 21000123100.

It is a congruent number.

It is an unprimeable number.

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, 350924 + ... + 406383.

It is an arithmetic number, because the mean of its divisors is an integer number (1226838960).

Almost surely, 2^21000123110 is an apocalyptic number.

21000123110 is a deficient number, since it is larger than the sum of its proper divisors (18258723610).

21000123110 is a wasteful number, since it uses less digits than its factorization.

21000123110 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 757420.

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

Adding to 21000123110 its reverse (1132100012), we get a palindrome (22132223122).

The spelling of 21000123110 in words is "twenty-one billion, one hundred twenty-three thousand, one hundred ten".