21020001221101 has 4 divisors (see below), whose sum is σ = 21216449830752. Its totient is φ = 20823552611452.

The previous prime is 21020001221099. The next prime is 21020001221123. The reversal of 21020001221101 is 10112210002012.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21020001221101 - 2¹ = 21020001221099 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 (21020001251101) 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, 98224304665 + ... + 98224304878.

It is an arithmetic number, because the mean of its divisors is an integer number (5304112457688).

Almost surely, 2^{21020001221101} is an apocalyptic number.

It is an amenable number.

21020001221101 is a deficient number, since it is larger than the sum of its proper divisors (196448609651).

21020001221101 is a wasteful number, since it uses less digits than its factorization.

21020001221101 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 196448609650.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 21020001221101 its reverse (10112210002012), we get a palindrome (31132211223113).

The spelling of 21020001221101 in words is "twenty-one trillion, twenty billion, one million, two hundred twenty-one thousand, one hundred one".