100001220 has 48 divisors (see below), whose sum is σ = 305460288. Its totient is φ = 24242560.

The previous prime is 100001219. The next prime is 100001227. The reversal of 100001220 is 22100001.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (6).

It is a super Niven number, because it is divisible the sum of any subset of its (nonzero) digits.

It is a junction number, because it is equal to n+sod(n) for n = 100001199 and 100001208.

It is not an unprimeable number, because it can be changed into a prime (100001227) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 75099 + ... + 76418.

It is an arithmetic number, because the mean of its divisors is an integer number (6363756).

Almost surely, 2^100001220 is an apocalyptic number.

100001220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

100001220 is an abundant number, since it is smaller than the sum of its proper divisors (205459068).

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

100001220 is a wasteful number, since it uses less digits than its factorization.

100001220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 151540 (or 151538 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 6.

The square root of 100001220 is about 10000.0609998140. The cubic root of 100001220 is about 464.1607709331.

Adding to 100001220 its reverse (22100001), we get a palindrome (122101221).

The spelling of 100001220 in words is "one hundred million, one thousand, two hundred twenty".