210121211100 has 72 divisors (see below), whose sum is σ = 608383404720. Its totient is φ = 55992442880.

The previous prime is 210121211059. The next prime is 210121211101. The reversal of 210121211100 is 1112121012.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (210121211101) 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, 174154 + ... + 671246.

It is an arithmetic number, because the mean of its divisors is an integer number (8449769510).

Almost surely, 2^210121211100 is an apocalyptic number.

210121211100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

210121211100 is an abundant number, since it is smaller than the sum of its proper divisors (398262193620).

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

210121211100 is a wasteful number, since it uses less digits than its factorization.

210121211100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 498519 (or 498512 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 12.

Adding to 210121211100 its reverse (1112121012), we get a palindrome (211233332112).

The spelling of 210121211100 in words is "two hundred ten billion, one hundred twenty-one million, two hundred eleven thousand, one hundred".