1221202100100 has 72 divisors (see below), whose sum is σ = 3533833729888. Its totient is φ = 325608825600.

The previous prime is 1221202100087. The next prime is 1221202100113. The reversal of 1221202100100 is 10012021221.

It is an interprime number because it is at equal distance from previous prime (1221202100087) and next prime (1221202100113).

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1918287 + ... + 2474313.

Almost surely, 2^{1221202100100} is an apocalyptic number.

1221202100100 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1221202100100 is an abundant number, since it is smaller than the sum of its proper divisors (2312631629788).

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

1221202100100 is a wasteful number, since it uses less digits than its factorization.

1221202100100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 563365 (or 563358 counting only the distinct ones).

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

Adding to 1221202100100 its reverse (10012021221), we get a palindrome (1231214121321).

The spelling of 1221202100100 in words is "one trillion, two hundred twenty-one billion, two hundred two million, one hundred thousand, one hundred".