212121331 has 8 divisors (see below), whose sum is σ = 217489104. Its totient is φ = 206762880.

The previous prime is 212121319. The next prime is 212121379. The reversal of 212121331 is 133121212.

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-212121331 is a prime.

It is a super-2 number, since 2×212121331² = 89990918130423122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (212121031) 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, 76831 + ... + 79543.

It is an arithmetic number, because the mean of its divisors is an integer number (27186138).

Almost surely, 2^212121331 is an apocalyptic number.

212121331 is a deficient number, since it is larger than the sum of its proper divisors (5367773).

212121331 is a wasteful number, since it uses less digits than its factorization.

212121331 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4661.

The product of its digits is 72, while the sum is 16.

The square root of 212121331 is about 14564.3857062356. The cubic root of 212121331 is about 596.3869263181.

Adding to 212121331 its reverse (133121212), we get a palindrome (345242543).

The spelling of 212121331 in words is "two hundred twelve million, one hundred twenty-one thousand, three hundred thirty-one".