21111010210121 has 16 divisors (see below), whose sum is σ = 22749462489600. Its totient is φ = 19474635022848.

The previous prime is 21111010210117. The next prime is 21111010210139. The reversal of 21111010210121 is 12101201011112.

It is a cyclic number.

It is not a de Polignac number, because 21111010210121 - 2² = 21111010210117 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21111010210096 and 21111010210105.

It is not an unprimeable number, because it can be changed into a prime (21111010210021) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 477829610 + ... + 477873788.

It is an arithmetic number, because the mean of its divisors is an integer number (1421841405600).

Almost surely, 2^{21111010210121} is an apocalyptic number.

It is an amenable number.

21111010210121 is a deficient number, since it is larger than the sum of its proper divisors (1638452279479).

21111010210121 is a wasteful number, since it uses less digits than its factorization.

21111010210121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66848.

The product of its (nonzero) digits is 8, while the sum is 14.

Adding to 21111010210121 its reverse (12101201011112), we get a palindrome (33212211221233).

The spelling of 21111010210121 in words is "twenty-one trillion, one hundred eleven billion, ten million, two hundred ten thousand, one hundred twenty-one".