21101011012121 has 8 divisors (see below), whose sum is σ = 21117091122120. Its totient is φ = 21084934620672.

The previous prime is 21101011012057. The next prime is 21101011012139. The reversal of 21101011012121 is 12121011010112.

It can be written as a sum of positive squares in 4 ways, for example, as 7470442370521 + 13630568641600 = 2733211^2 + 3691960^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21101011012121 - 2⁶ = 21101011012057 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21101011012096 and 21101011012105.

It is not an unprimeable number, because it can be changed into a prime (21101011032121) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10477001 + ... + 12327593.

It is an arithmetic number, because the mean of its divisors is an integer number (2639636390265).

Almost surely, 2^{21101011012121} is an apocalyptic number.

It is an amenable number.

21101011012121 is a deficient number, since it is larger than the sum of its proper divisors (16080109999).

21101011012121 is a wasteful number, since it uses less digits than its factorization.

21101011012121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1859275.

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

Adding to 21101011012121 its reverse (12121011010112), we get a palindrome (33222022022233).

The spelling of 21101011012121 in words is "twenty-one trillion, one hundred one billion, eleven million, twelve thousand, one hundred twenty-one".