21213202100 has 18 divisors (see below), whose sum is σ = 46032648774. Its totient is φ = 8485280800.

The previous prime is 21213202091. The next prime is 21213202103. The reversal of 21213202100 is 120231212.

It is a happy number.

It can be written as a sum of positive squares in 3 ways, for example, as 2556920356 + 18656281744 = 50566^2 + 136588^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21213202103) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 106065911 + ... + 106066110.

Almost surely, 2^21213202100 is an apocalyptic number.

21213202100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21213202100 is an abundant number, since it is smaller than the sum of its proper divisors (24819446674).

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

21213202100 is a wasteful number, since it uses less digits than its factorization.

21213202100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 212132035 (or 212132028 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 14.

Adding to 21213202100 its reverse (120231212), we get a palindrome (21333433312).

The spelling of 21213202100 in words is "twenty-one billion, two hundred thirteen million, two hundred two thousand, one hundred".