21010101312 has 112 divisors (see below), whose sum is σ = 57505071680. Its totient is φ = 6764746752.

The previous prime is 21010101283. The next prime is 21010101317. The reversal of 21010101312 is 21310101012.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is not an unprimeable number, because it can be changed into a prime (21010101317) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 976818 + ... + 998094.

It is an arithmetic number, because the mean of its divisors is an integer number (513438140).

Almost surely, 2^21010101312 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21010101312, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28752535840).

21010101312 is an abundant number, since it is smaller than the sum of its proper divisors (36494970368).

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

21010101312 is a wasteful number, since it uses less digits than its factorization.

21010101312 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21468 (or 21458 counting only the distinct ones).

The product of its (nonzero) digits is 12, while the sum is 12.

Adding to 21010101312 its reverse (21310101012), we get a palindrome (42320202324).

The spelling of 21010101312 in words is "twenty-one billion, ten million, one hundred one thousand, three hundred twelve".