101221200100 has 72 divisors (see below), whose sum is σ = 221990119848. Its totient is φ = 40057728000.

The previous prime is 101221200053. The next prime is 101221200103. The reversal of 101221200100 is 1002122101.

It can be written as a sum of positive squares in 12 ways, for example, as 23954991076 + 77266209024 = 154774^2 + 277968^2 .

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

It is not an unprimeable number, because it can be changed into a prime (101221200103) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 17702442 + ... + 17708158.

It is an arithmetic number, because the mean of its divisors is an integer number (3083196109).

Almost surely, 2^101221200100 is an apocalyptic number.

101221200100 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 101221200100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (110995059924).

101221200100 is an abundant number, since it is smaller than the sum of its proper divisors (120768919748).

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

101221200100 is a wasteful number, since it uses less digits than its factorization.

101221200100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7585 (or 7578 counting only the distinct ones).

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

Adding to 101221200100 its reverse (1002122101), we get a palindrome (102223322201).

The spelling of 101221200100 in words is "one hundred one billion, two hundred twenty-one million, two hundred thousand, one hundred".