21121122212 has 6 divisors (see below), whose sum is σ = 36961963878. Its totient is φ = 10560561104.

The previous prime is 21121122199. The next prime is 21121122221. The reversal of 21121122212 is 21222112112.

It can be written as a sum of positive squares in only one way, i.e., 20650839616 + 470282596 = 143704^2 + 21686^2 .

It is a super-2 number, since 2×21121122212² (a number of 21 digits) contains 22 as substring.

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 as a sum of consecutive naturals, namely, 2640140273 + ... + 2640140280.

It is an arithmetic number, because the mean of its divisors is an integer number (6160327313).

Almost surely, 2^21121122212 is an apocalyptic number.

It is an amenable number.

21121122212 is a deficient number, since it is larger than the sum of its proper divisors (15840841666).

21121122212 is a wasteful number, since it uses less digits than its factorization.

21121122212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5280280557 (or 5280280555 counting only the distinct ones).

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

Adding to 21121122212 its reverse (21222112112), we get a palindrome (42343234324).

The spelling of 21121122212 in words is "twenty-one billion, one hundred twenty-one million, one hundred twenty-two thousand, two hundred twelve".