210212021221 has 8 divisors (see below), whose sum is σ = 222598511640. Its totient is φ = 197827872768.

The previous prime is 210212021209. The next prime is 210212021269. The reversal of 210212021221 is 122120212012.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 2379976225 + 207832044996 = 48785^2 + 455886^2 .

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-210212021221 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 210212021195 and 210212021204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (210212021021) 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, 398986 + ... + 761323.

It is an arithmetic number, because the mean of its divisors is an integer number (27824813955).

Almost surely, 2^210212021221 is an apocalyptic number.

It is an amenable number.

210212021221 is a deficient number, since it is larger than the sum of its proper divisors (12386490419).

210212021221 is a wasteful number, since it uses less digits than its factorization.

210212021221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1170983.

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

Adding to 210212021221 its reverse (122120212012), we get a palindrome (332332233233).

The spelling of 210212021221 in words is "two hundred ten billion, two hundred twelve million, twenty-one thousand, two hundred twenty-one".