21201022202021 has 8 divisors (see below), whose sum is σ = 21321559574784. Its totient is φ = 21080795894640.

The previous prime is 21201022201999. The next prime is 21201022202033. The reversal of 21201022202021 is 12020222010212.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21201022202021 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 (21201022202221) 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, 77629646 + ... + 77902271.

It is an arithmetic number, because the mean of its divisors is an integer number (2665194946848).

Almost surely, 2^{21201022202021} is an apocalyptic number.

It is an amenable number.

21201022202021 is a deficient number, since it is larger than the sum of its proper divisors (120537372763).

21201022202021 is a wasteful number, since it uses less digits than its factorization.

21201022202021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 155532691.

The product of its (nonzero) digits is 128, while the sum is 17.

Adding to 21201022202021 its reverse (12020222010212), we get a palindrome (33221244212233).

The spelling of 21201022202021 in words is "twenty-one trillion, two hundred one billion, twenty-two million, two hundred two thousand, twenty-one".