21012210312 has 64 divisors (see below), whose sum is σ = 54362404800. Its totient is φ = 6762712320.

The previous prime is 21012210311. The next prime is 21012210377. The reversal of 21012210312 is 21301221012.

It is a junction number, because it is equal to n+sod(n) for n = 21012210291 and 21012210300.

It is not an unprimeable number, because it can be changed into a prime (21012210311) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 26014 + ... + 206642.

It is an arithmetic number, because the mean of its divisors is an integer number (849412575).

Almost surely, 2^21012210312 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 21012210312, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27181202400).

21012210312 is an abundant number, since it is smaller than the sum of its proper divisors (33350194488).

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

21012210312 is a wasteful number, since it uses less digits than its factorization.

21012210312 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 180806 (or 180802 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 15.

Adding to 21012210312 its reverse (21301221012), we get a palindrome (42313431324).

The spelling of 21012210312 in words is "twenty-one billion, twelve million, two hundred ten thousand, three hundred twelve".