100001221200 has 90 divisors (see below), whose sum is σ = 347032028174. Its totient is φ = 26666991360.

The previous prime is 100001221171. The next prime is 100001221223. The reversal of 100001221200 is 2122100001.

It can be written as a sum of positive squares in 3 ways, for example, as 1658769984 + 98342451216 = 40728^2 + 313596^2 .

It is a tau number, because it is divible by the number of its divisors (90).

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 13885459 + ... + 13892658.

Almost surely, 2^100001221200 is an apocalyptic number.

100001221200 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

100001221200 is an abundant number, since it is smaller than the sum of its proper divisors (247030806974).

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

100001221200 is a wasteful number, since it uses less digits than its factorization.

100001221200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27778141 (or 27778127 counting only the distinct ones).

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

Adding to 100001221200 its reverse (2122100001), we get a palindrome (102123321201).

It can be divided in two parts, 100001 and 221200, that added together give a triangular number (321201 = T₈₀₁).

The spelling of 100001221200 in words is "one hundred billion, one million, two hundred twenty-one thousand, two hundred".