21101220212 has 12 divisors (see below), whose sum is σ = 36928690176. Its totient is φ = 10550165880.

The previous prime is 21101220209. The next prime is 21101220253. The reversal of 21101220212 is 21202210112.

It is a super-2 number, since 2×21101220212² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

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, 10637 + ... + 205707.

It is an arithmetic number, because the mean of its divisors is an integer number (3077390848).

Almost surely, 2^21101220212 is an apocalyptic number.

It is an amenable number.

21101220212 is a deficient number, since it is larger than the sum of its proper divisors (15827469964).

21101220212 is a wasteful number, since it uses less digits than its factorization.

21101220212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 222118 (or 222116 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 21101220212 its reverse (21202210112), we get a palindrome (42303430324).

The spelling of 21101220212 in words is "twenty-one billion, one hundred one million, two hundred twenty thousand, two hundred twelve".