21112100010121 has 4 divisors (see below), whose sum is σ = 21112562259972. Its totient is φ = 21111637760272.

The previous prime is 21112100010103. The next prime is 21112100010163. The reversal of 21112100010121 is 12101000121112.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 12304738011721 + 8807361998400 = 3507811^2 + 2967720^2 .

It is a cyclic number.

It is not a de Polignac number, because 21112100010121 - 2¹³ = 21112100001929 is a prime.

It is a super-2 number, since 2×21112100010121² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21112100040121) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 231056410 + ... + 231147763.

It is an arithmetic number, because the mean of its divisors is an integer number (5278140564993).

Almost surely, 2^{21112100010121} is an apocalyptic number.

It is an amenable number.

21112100010121 is a deficient number, since it is larger than the sum of its proper divisors (462249851).

21112100010121 is an equidigital number, since it uses as much as digits as its factorization.

21112100010121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 462249850.

The product of its (nonzero) digits is 8, while the sum is 13.

Adding to 21112100010121 its reverse (12101000121112), we get a palindrome (33213100131233).

The spelling of 21112100010121 in words is "twenty-one trillion, one hundred twelve billion, one hundred million, ten thousand, one hundred twenty-one".