21213018000 has 240 divisors, whose sum is σ = 75815790336. Its totient is φ = 5525049600.

The previous prime is 21213017977. The next prime is 21213018011. The reversal of 21213018000 is 81031212.

It is a tau number, because it is divible by the number of its divisors (240).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 760297 + ... + 787703.

Almost surely, 2^21213018000 is an apocalyptic number.

21213018000 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 21213018000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37907895168).

21213018000 is an abundant number, since it is smaller than the sum of its proper divisors (54602772336).

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

21213018000 is a wasteful number, since it uses less digits than its factorization.

21213018000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27479 (or 27460 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 18.

Adding to 21213018000 its reverse (81031212), we get a palindrome (21294049212).

The spelling of 21213018000 in words is "twenty-one billion, two hundred thirteen million, eighteen thousand".