21312000000 has 546 divisors, whose sum is σ = 79029339974. Its totient is φ = 5529600000.

The previous prime is 21311999987. The next prime is 21312000029. The reversal of 21312000000 is 21312.

It is a happy number.

It can be written as a sum of positive squares in 7 ways, for example, as 20515405824 + 796594176 = 143232^2 + 28224^2 .

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a congruent number.

It is an unprimeable number.

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 41 ways as a sum of consecutive naturals, for example, 575999982 + ... + 576000018.

Almost surely, 2^21312000000 is an apocalyptic number.

21312000000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21312000000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39514669987).

21312000000 is an abundant number, since it is smaller than the sum of its proper divisors (57717339974).

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

21312000000 is an frugal number, since it uses more digits than its factorization.

21312000000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 97 (or 47 counting only the distinct ones).

The product of its (nonzero) digits is 12, while the sum is 9.

Adding to 21312000000 its reverse (21312), we get a palindrome (21312021312).

Multiplying 21312000000 by its reverse (21312), we get a square (454201344000000 = 21312000²).

21312000000 divided by its reverse (21312) gives a 6-th power (1000000 = 10⁶).

The spelling of 21312000000 in words is "twenty-one billion, three hundred twelve million", and thus it is an aban number.