21020201122221 has 12 divisors (see below), whose sum is σ = 34700014551072. Its totient is φ = 12011543498376.

The previous prime is 21020201122211. The next prime is 21020201122231. The reversal of 21020201122221 is 12222110202012.

It is a happy number.

21020201122221 is a `hidden beast` number, since 210 + 20 + 201 + 12 + 2 + 221 = 666.

It is an interprime number because it is at equal distance from previous prime (21020201122211) and next prime (21020201122231).

It is not a de Polignac number, because 21020201122221 - 2¹⁷ = 21020200991149 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21020201122194 and 21020201122203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21020201122211) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 166826992971 + ... + 166826993096.

It is an arithmetic number, because the mean of its divisors is an integer number (2891667879256).

Almost surely, 2^{21020201122221} is an apocalyptic number.

21020201122221 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

21020201122221 is a deficient number, since it is larger than the sum of its proper divisors (13679813428851).

21020201122221 is a wasteful number, since it uses less digits than its factorization.

21020201122221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 333653986080 (or 333653986077 counting only the distinct ones).

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

Adding to 21020201122221 its reverse (12222110202012), we get a palindrome (33242311324233).

The spelling of 21020201122221 in words is "twenty-one trillion, twenty billion, two hundred one million, one hundred twenty-two thousand, two hundred twenty-one".