21011102022121 has 4 divisors (see below), whose sum is σ = 21011984828244. Its totient is φ = 21010219216000.

The previous prime is 21011102022019. The next prime is 21011102022137. The reversal of 21011102022121 is 12122020111012.

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 19160413862121 + 1850688160000 = 4377261^2 + 1360400^2 .

It is a cyclic number.

It is not a de Polignac number, because 21011102022121 - 2¹⁹ = 21011101497833 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21011102022095 and 21011102022104.

It is not an unprimeable number, because it can be changed into a prime (21011102028121) 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, 441367360 + ... + 441414961.

It is an arithmetic number, because the mean of its divisors is an integer number (5252996207061).

Almost surely, 2^{21011102022121} is an apocalyptic number.

It is an amenable number.

21011102022121 is a deficient number, since it is larger than the sum of its proper divisors (882806123).

21011102022121 is an equidigital number, since it uses as much as digits as its factorization.

21011102022121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 882806122.

The product of its (nonzero) digits is 32, while the sum is 16.

Adding to 21011102022121 its reverse (12122020111012), we get a palindrome (33133122133133).

The spelling of 21011102022121 in words is "twenty-one trillion, eleven billion, one hundred two million, twenty-two thousand, one hundred twenty-one".