21021212122 has 8 divisors (see below), whose sum is σ = 31604641236. Its totient is φ = 10486331712.

The previous prime is 21021212117. The next prime is 21021212141. The reversal of 21021212122 is 22121212012.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 17537969761 + 3483242361 = 132431^2 + 59019^2 .

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

It is a junction number, because it is equal to n+sod(n) for n = 21021212096 and 21021212105.

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, 12136093 + ... + 12137824.

Almost surely, 2^21021212122 is an apocalyptic number.

21021212122 is a deficient number, since it is larger than the sum of its proper divisors (10583429114).

21021212122 is a wasteful number, since it uses less digits than its factorization.

21021212122 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24274352.

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 21021212122 its reverse (22121212012), we get a palindrome (43142424134).

The spelling of 21021212122 in words is "twenty-one billion, twenty-one million, two hundred twelve thousand, one hundred twenty-two".