21202012202021 has 16 divisors (see below), whose sum is σ = 24244433015040. Its totient is φ = 18162984698880.

The previous prime is 21202012201963. The next prime is 21202012202087. The reversal of 21202012202021 is 12020221020212.

It is a happy number.

It is a de Polignac number, because none of the positive numbers 2^k-21202012202021 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21202012202321) 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, 92750456 + ... + 92978766.

It is an arithmetic number, because the mean of its divisors is an integer number (1515277063440).

Almost surely, 2^{21202012202021} is an apocalyptic number.

It is an amenable number.

21202012202021 is a deficient number, since it is larger than the sum of its proper divisors (3042420813019).

21202012202021 is a wasteful number, since it uses less digits than its factorization.

21202012202021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 235684.

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

Adding to 21202012202021 its reverse (12020221020212), we get a palindrome (33222233222233).

The spelling of 21202012202021 in words is "twenty-one trillion, two hundred two billion, twelve million, two hundred two thousand, twenty-one".