100001211220 has 12 divisors (see below), whose sum is σ = 210002543604. Its totient is φ = 40000484480.

The previous prime is 100001211203. The next prime is 100001211221. The reversal of 100001211220 is 22112100001.

It can be written as a sum of positive squares in 2 ways, for example, as 67975961284 + 32025249936 = 260722^2 + 178956^2 .

It is a Harshad number since it is a multiple of its sum of digits (10).

It is a junction number, because it is equal to n+sod(n) for n = 100001211197 and 100001211206.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (100001211221) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2500030261 + ... + 2500030300.

It is an arithmetic number, because the mean of its divisors is an integer number (17500211967).

Almost surely, 2^100001211220 is an apocalyptic number.

100001211220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

100001211220 is an abundant number, since it is smaller than the sum of its proper divisors (110001332384).

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

100001211220 is a wasteful number, since it uses less digits than its factorization.

100001211220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5000060570 (or 5000060568 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 10.

Adding to 100001211220 its reverse (22112100001), we get a palindrome (122113311221).

The spelling of 100001211220 in words is "one hundred billion, one million, two hundred eleven thousand, two hundred twenty".