1211212221100 has 72 divisors (see below), whose sum is σ = 3003964865888. Its totient is φ = 415250841600.

The previous prime is 1211212221073. The next prime is 1211212221119. The reversal of 1211212221100 is 11222121121.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 18742444 + ... + 18806956.

Almost surely, 2^{1211212221100} is an apocalyptic number.

1211212221100 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1211212221100 is an abundant number, since it is smaller than the sum of its proper divisors (1792752644788).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1211212221100 is a wasteful number, since it uses less digits than its factorization.

1211212221100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 91355 (or 91348 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 16.

Adding to 1211212221100 its reverse (11222121121), we get a palindrome (1222434342221).

The spelling of 1211212221100 in words is "one trillion, two hundred eleven billion, two hundred twelve million, two hundred twenty-one thousand, one hundred".