21121021121212 has 6 divisors (see below), whose sum is σ = 36961786962128. Its totient is φ = 10560510560604.

The previous prime is 21121021121209. The next prime is 21121021121273. The reversal of 21121021121212 is 21212112012112.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 21121021121212.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2640127640148 + ... + 2640127640155.

Almost surely, 2^{21121021121212} is an apocalyptic number.

It is an amenable number.

21121021121212 is a deficient number, since it is larger than the sum of its proper divisors (15840765840916).

21121021121212 is a wasteful number, since it uses less digits than its factorization.

21121021121212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5280255280307 (or 5280255280305 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 19.

Adding to 21121021121212 its reverse (21212112012112), we get a palindrome (42333133133324).

The spelling of 21121021121212 in words is "twenty-one trillion, one hundred twenty-one billion, twenty-one million, one hundred twenty-one thousand, two hundred twelve".