21202021111021 has 16 divisors (see below), whose sum is σ = 23547896322048. Its totient is φ = 18987308243200.

The previous prime is 21202021111013. The next prime is 21202021111039. The reversal of 21202021111021 is 12011112020212.

It is a cyclic number.

It is not a de Polignac number, because 21202021111021 - 2³ = 21202021111013 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21202021110986 and 21202021111004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21202021111321) 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, 141875890 + ... + 142025251.

It is an arithmetic number, because the mean of its divisors is an integer number (1471743520128).

Almost surely, 2^{21202021111021} is an apocalyptic number.

It is an amenable number.

21202021111021 is a deficient number, since it is larger than the sum of its proper divisors (2345875211027).

21202021111021 is a wasteful number, since it uses less digits than its factorization.

21202021111021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 283901372.

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

Adding to 21202021111021 its reverse (12011112020212), we get a palindrome (33213133131233).

The spelling of 21202021111021 in words is "twenty-one trillion, two hundred two billion, twenty-one million, one hundred eleven thousand, twenty-one".