211221212120 has 16 divisors (see below), whose sum is σ = 475247727360. Its totient is φ = 84488484832.

The previous prime is 211221212113. The next prime is 211221212129. The reversal of 211221212120 is 21212122112.

It is a super-2 number, since 2×211221212120² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211221212129) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2640265112 + ... + 2640265191.

It is an arithmetic number, because the mean of its divisors is an integer number (29702982960).

Almost surely, 2^211221212120 is an apocalyptic number.

211221212120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

211221212120 is an abundant number, since it is smaller than the sum of its proper divisors (264026515240).

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

211221212120 is a wasteful number, since it uses less digits than its factorization.

211221212120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5280530314 (or 5280530310 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 211221212120 its reverse (21212122112), we get a palindrome (232433334232).

The spelling of 211221212120 in words is "two hundred eleven billion, two hundred twenty-one million, two hundred twelve thousand, one hundred twenty".