20021100021205 has 16 divisors (see below), whose sum is σ = 24576919787520. Its totient is φ = 15650269696512.

The previous prime is 20021100021203. The next prime is 20021100021257. The reversal of 20021100021205 is 50212000112002.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 20021100021205 - 2¹ = 20021100021203 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20021100021203) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 70035420 + ... + 70320709.

It is an arithmetic number, because the mean of its divisors is an integer number (1536057486720).

Almost surely, 2^{20021100021205} is an apocalyptic number.

It is an amenable number.

20021100021205 is a deficient number, since it is larger than the sum of its proper divisors (4555819766315).

20021100021205 is a wasteful number, since it uses less digits than its factorization.

20021100021205 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 140356788.

The product of its (nonzero) digits is 80, while the sum is 16.

Adding to 20021100021205 its reverse (50212000112002), we get a palindrome (70233100133207).

The spelling of 20021100021205 in words is "twenty trillion, twenty-one billion, one hundred million, twenty-one thousand, two hundred five".