21001210202221 has 8 divisors (see below), whose sum is σ = 22263994234944. Its totient is φ = 19741472694720.

The previous prime is 21001210202213. The next prime is 21001210202233. The reversal of 21001210202221 is 12220201210012.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21001210202221 - 2³ = 21001210202213 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21001210202195 and 21001210202204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21001210202201) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 761617105 + ... + 761644678.

It is an arithmetic number, because the mean of its divisors is an integer number (2782999279368).

Almost surely, 2^{21001210202221} is an apocalyptic number.

It is an amenable number.

21001210202221 is a deficient number, since it is larger than the sum of its proper divisors (1262784032723).

21001210202221 is a wasteful number, since it uses less digits than its factorization.

21001210202221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1523262611.

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 21001210202221 its reverse (12220201210012), we get a palindrome (33221411412233).

The spelling of 21001210202221 in words is "twenty-one trillion, one billion, two hundred ten million, two hundred two thousand, two hundred twenty-one".