1221002201100 has 144 divisors (see below), whose sum is σ = 3908208358656. Its totient is φ = 291831456000.

The previous prime is 1221002201053. The next prime is 1221002201101. The reversal of 1221002201100 is 11022001221.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is not an unprimeable number, because it can be changed into a prime (1221002201101) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2371339 + ... + 2839938.

It is an arithmetic number, because the mean of its divisors is an integer number (27140335824).

Almost surely, 2^{1221002201100} is an apocalyptic number.

1221002201100 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1221002201100 is an abundant number, since it is smaller than the sum of its proper divisors (2687206157556).

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

1221002201100 is a wasteful number, since it uses less digits than its factorization.

1221002201100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5211376 (or 5211369 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 12.

Adding to 1221002201100 its reverse (11022001221), we get a palindrome (1232024202321).

The spelling of 1221002201100 in words is "one trillion, two hundred twenty-one billion, two million, two hundred one thousand, one hundred".