21220210100 has 36 divisors (see below), whose sum is σ = 47170983468. Its totient is φ = 8281056000.

The previous prime is 21220210087. The next prime is 21220210133. The reversal of 21220210100 is 101202212.

It is a happy number.

It can be written as a sum of positive squares in 6 ways, for example, as 24344356 + 21195865744 = 4934^2 + 145588^2 .

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, 2583731 + ... + 2591930.

Almost surely, 2^21220210100 is an apocalyptic number.

21220210100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21220210100 is an abundant number, since it is smaller than the sum of its proper divisors (25950773368).

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

21220210100 is a wasteful number, since it uses less digits than its factorization.

21220210100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5175716 (or 5175709 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 11.

Adding to 21220210100 its reverse (101202212), we get a palindrome (21321412312).

The spelling of 21220210100 in words is "twenty-one billion, two hundred twenty million, two hundred ten thousand, one hundred".