21313212102 has 128 divisors (see below), whose sum is σ = 58871070720. Its totient is φ = 5565283200.

The previous prime is 21313212061. The next prime is 21313212169. The reversal of 21313212102 is 20121231312.

21313212102 is a `hidden beast` number, since 2 + 131 + 321 + 210 + 2 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 474843 + ... + 517785.

It is an arithmetic number, because the mean of its divisors is an integer number (459930240).

Almost surely, 2^21313212102 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21313212102, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29435535360).

21313212102 is an abundant number, since it is smaller than the sum of its proper divisors (37557858618).

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

21313212102 is a wasteful number, since it uses less digits than its factorization.

21313212102 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43075 (or 43069 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

Adding to 21313212102 its reverse (20121231312), we get a palindrome (41434443414).

The spelling of 21313212102 in words is "twenty-one billion, three hundred thirteen million, two hundred twelve thousand, one hundred two".