21011210210221 has 32 divisors (see below), whose sum is σ = 27588804203520. Its totient is φ = 15502633286400.

The previous prime is 21011210210201. The next prime is 21011210210231. The reversal of 21011210210221 is 12201201211012.

It is a cyclic number.

It is not a de Polignac number, because 21011210210221 - 2¹⁷ = 21011210079149 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21011210210195 and 21011210210204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21011210210201) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 893676 + ... + 6543781.

It is an arithmetic number, because the mean of its divisors is an integer number (862150131360).

Almost surely, 2^{21011210210221} is an apocalyptic number.

It is an amenable number.

21011210210221 is a deficient number, since it is larger than the sum of its proper divisors (6577593993299).

21011210210221 is a wasteful number, since it uses less digits than its factorization.

21011210210221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7439425.

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

Adding to 21011210210221 its reverse (12201201211012), we get a palindrome (33212411421233).

The spelling of 21011210210221 in words is "twenty-one trillion, eleven billion, two hundred ten million, two hundred ten thousand, two hundred twenty-one".