1211223021100 has 72 divisors (see below), whose sum is σ = 2673338214848. Its totient is φ = 476208460800.

The previous prime is 1211223021091. The next prime is 1211223021131. The reversal of 1211223021100 is 11203221121.

It is a super-2 number, since 2×1211223021100² (a number of 25 digits) contains 22 as substring.

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, 8610532 + ... + 8750068.

Almost surely, 2^{1211223021100} is an apocalyptic number.

1211223021100 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1211223021100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1336669107424).

1211223021100 is an abundant number, since it is smaller than the sum of its proper divisors (1462115193748).

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

1211223021100 is a wasteful number, since it uses less digits than its factorization.

1211223021100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 141035 (or 141028 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 16.

Adding to 1211223021100 its reverse (11203221121), we get a palindrome (1222426242221).

The spelling of 1211223021100 in words is "one trillion, two hundred eleven billion, two hundred twenty-three million, twenty-one thousand, one hundred".