21210220210100 has 36 divisors (see below), whose sum is σ = 46032067511724. Its totient is φ = 8483002433280.

The previous prime is 21210220210073. The next prime is 21210220210163. The reversal of 21210220210100 is 101202201212.

It can be written as a sum of positive squares in 6 ways, for example, as 919934193424 + 20290286016676 = 959132^2 + 4504474^2 .

It is a congruent number.

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, 12785027 + ... + 14348426.

Almost surely, 2^{21210220210100} is an apocalyptic number.

21210220210100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21210220210100 is an abundant number, since it is smaller than the sum of its proper divisors (24821847301624).

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

21210220210100 is a wasteful number, since it uses less digits than its factorization.

21210220210100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27141284 (or 27141277 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 21210220210100 its reverse (101202201212), we get a palindrome (21311422411312).

The spelling of 21210220210100 in words is "twenty-one trillion, two hundred ten billion, two hundred twenty million, two hundred ten thousand, one hundred".