100001201220 has 36 divisors (see below), whose sum is σ = 303336977580. Its totient is φ = 26666986944.

The previous prime is 100001201189. The next prime is 100001201257. The reversal of 100001201220 is 22102100001.

It can be written as a sum of positive squares in 2 ways, for example, as 29721070404 + 70280130816 = 172398^2 + 265104^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (9).

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 277780935 + ... + 277781294.

It is an arithmetic number, because the mean of its divisors is an integer number (8426027155).

Almost surely, 2^100001201220 is an apocalyptic number.

100001201220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

100001201220 is an abundant number, since it is smaller than the sum of its proper divisors (203335776360).

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

100001201220 is a wasteful number, since it uses less digits than its factorization.

100001201220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 555562244 (or 555562239 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 9.

Adding to 100001201220 its reverse (22102100001), we get a palindrome (122103301221).

The spelling of 100001201220 in words is "one hundred billion, one million, two hundred one thousand, two hundred twenty".