201021200100 has 216 divisors, whose sum is σ = 737667036288. Its totient is φ = 44826969600.

The previous prime is 201021200077. The next prime is 201021200123. The reversal of 201021200100 is 1002120102.

It is an interprime number because it is at equal distance from previous prime (201021200077) and next prime (201021200123).

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 71 ways as a sum of consecutive naturals, for example, 130824 + ... + 647423.

It is an arithmetic number, because the mean of its divisors is an integer number (3415125168).

Almost surely, 2^201021200100 is an apocalyptic number.

201021200100 is a gapful number since it is divisible by the number (20) 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 201021200100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (368833518144).

201021200100 is an abundant number, since it is smaller than the sum of its proper divisors (536645836188).

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

201021200100 is a wasteful number, since it uses less digits than its factorization.

201021200100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 778315 (or 778305 counting only the distinct ones).

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

Adding to 201021200100 its reverse (1002120102), we get a palindrome (202023320202).

The spelling of 201021200100 in words is "two hundred one billion, twenty-one million, two hundred thousand, one hundred".