210121100 has 144 divisors (see below), whose sum is σ = 562630656. Its totient is φ = 66528000.

The previous prime is 210121063. The next prime is 210121103. The reversal of 210121100 is 1121012.

It is not an unprimeable number, because it can be changed into a prime (210121103) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 498890 + ... + 499310.

Almost surely, 2^210121100 is an apocalyptic number.

210121100 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 210121100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (281315328).

210121100 is an abundant number, since it is smaller than the sum of its proper divisors (352509556).

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

210121100 is a wasteful number, since it uses less digits than its factorization.

210121100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 496 (or 489 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 8.

The square root of 210121100 is about 14495.5544909465. The cubic root of 210121100 is about 594.5064287096.

Adding to 210121100 its reverse (1121012), we get a palindrome (211242112).

The spelling of 210121100 in words is "two hundred ten million, one hundred twenty-one thousand, one hundred".