21011121212 has 6 divisors (see below), whose sum is σ = 36769462128. Its totient is φ = 10505560604.

The previous prime is 21011121179. The next prime is 21011121227. The reversal of 21011121212 is 21212111012.

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, 2626390148 + ... + 2626390155.

It is an arithmetic number, because the mean of its divisors is an integer number (6128243688).

Almost surely, 2^21011121212 is an apocalyptic number.

It is an amenable number.

21011121212 is a deficient number, since it is larger than the sum of its proper divisors (15758340916).

21011121212 is a wasteful number, since it uses less digits than its factorization.

21011121212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5252780307 (or 5252780305 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 14.

Adding to 21011121212 its reverse (21212111012), we get a palindrome (42223232224).

The spelling of 21011121212 in words is "twenty-one billion, eleven million, one hundred twenty-one thousand, two hundred twelve".