210001100121220 has 24 divisors (see below), whose sum is σ = 441008438905944. Its totient is φ = 83999272686336.

The previous prime is 210001100121079. The next prime is 210001100121223. The reversal of 210001100121220 is 22121001100012.

It can be written as a sum of positive squares in 4 ways, for example, as 55437674139904 + 154563425981316 = 7445648^2 + 12432354^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 210001100121220.

It is not an unprimeable number, because it can be changed into a prime (210001100121223) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 71484279 + ... + 74363998.

It is an arithmetic number, because the mean of its divisors is an integer number (18375351621081).

Almost surely, 2^{210001100121220} is an apocalyptic number.

210001100121220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

210001100121220 is an abundant number, since it is smaller than the sum of its proper divisors (231007338784724).

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

210001100121220 is a wasteful number, since it uses less digits than its factorization.

210001100121220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 145920279 (or 145920277 counting only the distinct ones).

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

Adding to 210001100121220 its reverse (22121001100012), we get a palindrome (232122101221232).

The spelling of 210001100121220 in words is "two hundred ten trillion, one billion, one hundred million, one hundred twenty-one thousand, two hundred twenty".