211212111121221 has 8 divisors (see below), whose sum is σ = 321847026470464. Its totient is φ = 120692634926400.

The previous prime is 211212111121217. The next prime is 211212111121283. The reversal of 211212111121221 is 122121111212112.

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

It is not a de Polignac number, because 211212111121221 - 2² = 211212111121217 is a prime.

It is a super-2 number, since 2×211212111121221² (a number of 29 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (21), and also a Moran number because the ratio is a prime number: 10057719577201 = 211212111121221 / (2 + 1 + 1 + 2 + 1 + 2 + 1 + 1 + 1 + 1 + 2 + 1 + 2 + 2 + 1).

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211212111121321) 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, 5028859788580 + ... + 5028859788621.

It is an arithmetic number, because the mean of its divisors is an integer number (40230878308808).

Almost surely, 2^{211212111121221} is an apocalyptic number.

211212111121221 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

211212111121221 is a deficient number, since it is larger than the sum of its proper divisors (110634915349243).

211212111121221 is a wasteful number, since it uses less digits than its factorization.

211212111121221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10057719577211.

The product of its digits is 64, while the sum is 21.

Adding to 211212111121221 its reverse (122121111212112), we get a palindrome (333333222333333).

The spelling of 211212111121221 in words is "two hundred eleven trillion, two hundred twelve billion, one hundred eleven million, one hundred twenty-one thousand, two hundred twenty-one".