21010121011121 has 16 divisors (see below), whose sum is σ = 23494376965248. Its totient is φ = 18622176412800.

The previous prime is 21010121011079. The next prime is 21010121011169. The reversal of 21010121011121 is 12111012101012.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21010121011121 is a prime.

It is a super-2 number, since 2×21010121011121² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21010121011096 and 21010121011105.

It is not an unprimeable number, because it can be changed into a prime (21010121011171) 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, 14399906 + ... + 15791691.

It is an arithmetic number, because the mean of its divisors is an integer number (1468398560328).

Almost surely, 2^{21010121011121} is an apocalyptic number.

It is an amenable number.

21010121011121 is a deficient number, since it is larger than the sum of its proper divisors (2484255954127).

21010121011121 is a wasteful number, since it uses less digits than its factorization.

21010121011121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30193192.

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

Adding to 21010121011121 its reverse (12111012101012), we get a palindrome (33121133112133).

The spelling of 21010121011121 in words is "twenty-one trillion, ten billion, one hundred twenty-one million, eleven thousand, one hundred twenty-one".