21202110222021 has 6 divisors (see below), whose sum is σ = 30625270320710. Its totient is φ = 14134740148008.

The previous prime is 21202110221987. The next prime is 21202110222031. The reversal of 21202110222021 is 12022201120212.

It is a happy number.

21202110222021 is a `hidden beast` number, since 212 + 0 + 211 + 0 + 2 + 220 + 21 = 666.

It can be written as a sum of positive squares in only one way, i.e., 13525808285025 + 7676301936996 = 3677745^2 + 2770614^2 .

It is not a de Polignac number, because 21202110222021 - 2¹⁷ = 21202110090949 is a prime.

It is a super-3 number, since 3×21202110222021³ (a number of 41 digits) contains 333 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21202110221985 and 21202110222003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21202110222031) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1177895012326 + ... + 1177895012343.

Almost surely, 2^{21202110222021} is an apocalyptic number.

It is an amenable number.

21202110222021 is a deficient number, since it is larger than the sum of its proper divisors (9423160098689).

21202110222021 is a wasteful number, since it uses less digits than its factorization.

21202110222021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2355790024675 (or 2355790024672 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

Adding to 21202110222021 its reverse (12022201120212), we get a palindrome (33224311342233).

The spelling of 21202110222021 in words is "twenty-one trillion, two hundred two billion, one hundred ten million, two hundred twenty-two thousand, twenty-one".