210121212100 has 36 divisors (see below), whose sum is σ = 482784388884. Its totient is φ = 79104455680.

The previous prime is 210121212071. The next prime is 210121212101. The reversal of 210121212100 is 1212121012.

It can be written as a sum of positive squares in 6 ways, for example, as 2389449924 + 207731762176 = 48882^2 + 455776^2 .

It is not an unprimeable number, because it can be changed into a prime (210121212101) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 61798657 + ... + 61802056.

It is an arithmetic number, because the mean of its divisors is an integer number (13410677469).

Almost surely, 2^210121212100 is an apocalyptic number.

210121212100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

210121212100 is an abundant number, since it is smaller than the sum of its proper divisors (272663176784).

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

210121212100 is a wasteful number, since it uses less digits than its factorization.

210121212100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 123600744 (or 123600737 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 210121212100 its reverse (1212121012), we get a palindrome (211333333112).

The spelling of 210121212100 in words is "two hundred ten billion, one hundred twenty-one million, two hundred twelve thousand, one hundred".