21012121112101 has 8 divisors (see below), whose sum is σ = 24014723523584. Its totient is φ = 18009736406640.

The previous prime is 21012121112051. The next prime is 21012121112113. The reversal of 21012121112101 is 10121112121012.

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 21012121112101 - 2¹⁹ = 21012120587813 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21012121112161) 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, 54219630 + ... + 54605791.

It is an arithmetic number, because the mean of its divisors is an integer number (3001840440448).

Almost surely, 2^{21012121112101} is an apocalyptic number.

It is an amenable number.

21012121112101 is a deficient number, since it is larger than the sum of its proper divisors (3002602411483).

21012121112101 is a wasteful number, since it uses less digits than its factorization.

21012121112101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 108853011.

The product of its (nonzero) digits is 16, while the sum is 16.

Adding to 21012121112101 its reverse (10121112121012), we get a palindrome (31133233233113).

The spelling of 21012121112101 in words is "twenty-one trillion, twelve billion, one hundred twenty-one million, one hundred twelve thousand, one hundred one".