21212310100 has 36 divisors (see below), whose sum is σ = 46233540864. Its totient is φ = 8447536480.

The previous prime is 21212310037. The next prime is 21212310103. The reversal of 21212310100 is 101321212.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21212310103) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 444532 + ... + 489931.

It is an arithmetic number, because the mean of its divisors is an integer number (1284265024).

Almost surely, 2^21212310100 is an apocalyptic number.

21212310100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21212310100 is an abundant number, since it is smaller than the sum of its proper divisors (25021230764).

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

21212310100 is a wasteful number, since it uses less digits than its factorization.

21212310100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 934704 (or 934697 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 13.

Adding to 21212310100 its reverse (101321212), we get a palindrome (21313631312).

The spelling of 21212310100 in words is "twenty-one billion, two hundred twelve million, three hundred ten thousand, one hundred".