21011020121101 has 8 divisors (see below), whose sum is σ = 21225028217400. Its totient is φ = 20797890908928.

The previous prime is 21011020121093. The next prime is 21011020121153. The reversal of 21011020121101 is 10112102011012.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 2442453237225 + 18568566883876 = 1562835^2 + 4309126^2 .

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 21011020121101 - 2³ = 21011020121093 is a prime.

It is a super-2 number, since 2×21011020121101² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21011020121801) 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, 219672976 + ... + 219768601.

It is an arithmetic number, because the mean of its divisors is an integer number (2653128527175).

Almost surely, 2^{21011020121101} is an apocalyptic number.

It is an amenable number.

21011020121101 is a deficient number, since it is larger than the sum of its proper divisors (214008096299).

21011020121101 is a wasteful number, since it uses less digits than its factorization.

21011020121101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 439442063.

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

Adding to 21011020121101 its reverse (10112102011012), we get a palindrome (31123122132113).

The spelling of 21011020121101 in words is "twenty-one trillion, eleven billion, twenty million, one hundred twenty-one thousand, one hundred one".