21210212220100 has 36 divisors (see below), whose sum is σ = 46362117923604. Its totient is φ = 8422157255680.

The previous prime is 21210212220073. The next prime is 21210212220181. The reversal of 21210212220100 is 102221201212.

It is a happy number.

It can be written as a sum of positive squares in 6 ways, for example, as 797291839744 + 20412920380356 = 892912^2 + 4518066^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 774081637 + ... + 774109036.

It is an arithmetic number, because the mean of its divisors is an integer number (1287836608989).

Almost surely, 2^{21210212220100} is an apocalyptic number.

21210212220100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21210212220100 is an abundant number, since it is smaller than the sum of its proper divisors (25151905703504).

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

21210212220100 is a wasteful number, since it uses less digits than its factorization.

21210212220100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1548190824 (or 1548190817 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 21210212220100 its reverse (102221201212), we get a palindrome (21312433421312).

The spelling of 21210212220100 in words is "twenty-one trillion, two hundred ten billion, two hundred twelve million, two hundred twenty thousand, one hundred".