1221100201100 has 72 divisors (see below), whose sum is σ = 2863701555120. Its totient is φ = 449274458880.

The previous prime is 1221100201067. The next prime is 1221100201129. The reversal of 1221100201100 is 11020011221.

It is a super-2 number, since 2×1221100201100² (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, 1291655 + ... + 2027454.

It is an arithmetic number, because the mean of its divisors is an integer number (39773632710).

Almost surely, 2^{1221100201100} is an apocalyptic number.

1221100201100 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1221100201100 is an abundant number, since it is smaller than the sum of its proper divisors (1642601354020).

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

1221100201100 is a wasteful number, since it uses less digits than its factorization.

1221100201100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3319419 (or 3319412 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 11.

Adding to 1221100201100 its reverse (11020011221), we get a palindrome (1232120212321).

The spelling of 1221100201100 in words is "one trillion, two hundred twenty-one billion, one hundred million, two hundred one thousand, one hundred".