21312033312 has 96 divisors (see below), whose sum is σ = 58714927488. Its totient is φ = 6755741696.

The previous prime is 21312033307. The next prime is 21312033343. The reversal of 21312033312 is 21333021312.

It is a tau number, because it is divible by the number of its divisors (96).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 354088 + ... + 409880.

It is an arithmetic number, because the mean of its divisors is an integer number (611613828).

Almost surely, 2^21312033312 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 21312033312, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29357463744).

21312033312 is an abundant number, since it is smaller than the sum of its proper divisors (37402894176).

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

21312033312 is a wasteful number, since it uses less digits than its factorization.

21312033312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56002 (or 55994 counting only the distinct ones).

The product of its (nonzero) digits is 648, while the sum is 21.

Adding to 21312033312 its reverse (21333021312), we get a palindrome (42645054624).

The spelling of 21312033312 in words is "twenty-one billion, three hundred twelve million, thirty-three thousand, three hundred twelve".