21212122 has 8 divisors (see below), whose sum is σ = 32844672. Its totient is φ = 10263900.

The previous prime is 21212119. The next prime is 21212131. The reversal of 21212122 is 22121212.

It is a happy number.

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

It is a nude number because it is divisible by every one of its digits.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 171004 + ... + 171127.

It is an arithmetic number, because the mean of its divisors is an integer number (4105584).

Almost surely, 2^21212122 is an apocalyptic number.

21212122 is a deficient number, since it is larger than the sum of its proper divisors (11632550).

21212122 is a wasteful number, since it uses less digits than its factorization.

21212122 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 342164.

The product of its digits is 32, while the sum is 13.

The square root of 21212122 is about 4605.6619502521. The cubic root of 21212122 is about 276.8182414861.

Adding to 21212122 its reverse (22121212), we get a palindrome (43333334).

It can be divided in two parts, 2121212 and 2, that multiplied together give a palindrome (4242424).

The spelling of 21212122 in words is "twenty-one million, two hundred twelve thousand, one hundred twenty-two".