21110210121 has 128 divisors (see below), whose sum is σ = 38603980800. Its totient is φ = 9907349760.

The previous prime is 21110210063. The next prime is 21110210131. The reversal of 21110210121 is 12101201112.

It is not a de Polignac number, because 21110210121 - 2⁶ = 21110210057 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21110210097 and 21110210106.

It is not an unprimeable number, because it can be changed into a prime (21110210131) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 48086820 + ... + 48087258.

It is an arithmetic number, because the mean of its divisors is an integer number (301593600).

Almost surely, 2^21110210121 is an apocalyptic number.

21110210121 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

21110210121 is a deficient number, since it is larger than the sum of its proper divisors (17493770679).

21110210121 is a wasteful number, since it uses less digits than its factorization.

21110210121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 779.

The product of its (nonzero) digits is 8, while the sum is 12.

Adding to 21110210121 its reverse (12101201112), we get a palindrome (33211411233).

Subtracting from 21110210121 its reverse (12101201112), we obtain a palindrome (9009009009).

The spelling of 21110210121 in words is "twenty-one billion, one hundred ten million, two hundred ten thousand, one hundred twenty-one".