21312111000 has 256 divisors, whose sum is σ = 69003342720. Its totient is φ = 5472000000.

The previous prime is 21312110993. The next prime is 21312111077. The reversal of 21312111000 is 11121312.

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

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, 11210050 + ... + 11211950.

Almost surely, 2^21312111000 is an apocalyptic number.

21312111000 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 21312111000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34501671360).

21312111000 is an abundant number, since it is smaller than the sum of its proper divisors (47691231720).

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

21312111000 is a wasteful number, since it uses less digits than its factorization.

21312111000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2063 (or 2049 counting only the distinct ones).

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

Adding to 21312111000 its reverse (11121312), we get a palindrome (21323232312).

The spelling of 21312111000 in words is "twenty-one billion, three hundred twelve million, one hundred eleven thousand".