212121222210 has 48 divisors (see below), whose sum is σ = 554286657600. Its totient is φ = 56281404960.

The previous prime is 212121222161. The next prime is 212121222223. The reversal of 212121222210 is 12222121212.

It is a happy number.

212121222210 is a `hidden beast` number, since 21 + 212 + 1 + 222 + 210 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 5903956 + ... + 5939775.

It is an arithmetic number, because the mean of its divisors is an integer number (11547638700).

Almost surely, 2^212121222210 is an apocalyptic number.

212121222210 is an abundant number, since it is smaller than the sum of its proper divisors (342165435390).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

212121222210 is a wasteful number, since it uses less digits than its factorization.

212121222210 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11843943 (or 11843940 counting only the distinct ones).

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

Adding to 212121222210 its reverse (12222121212), we get a palindrome (224343343422).

The spelling of 212121222210 in words is "two hundred twelve billion, one hundred twenty-one million, two hundred twenty-two thousand, two hundred ten".