21003312330 has 384 divisors, whose sum is σ = 75314244096. Its totient is φ = 3919104000.

The previous prime is 21003312299. The next prime is 21003312347. The reversal of 21003312330 is 3321330012.

21003312330 is a `hidden beast` number, since 2 + 1 + 0 + 0 + 331 + 2 + 330 = 666.

It is a super-2 number, since 2×21003312330² (a number of 21 digits) contains 22 as substring.

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

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 3330180 + ... + 3336480.

It is an arithmetic number, because the mean of its divisors is an integer number (196130844).

Almost surely, 2^21003312330 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21003312330, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37657122048).

21003312330 is an abundant number, since it is smaller than the sum of its proper divisors (54310931766).

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

21003312330 is a wasteful number, since it uses less digits than its factorization.

21003312330 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6382 (or 6379 counting only the distinct ones).

The product of its (nonzero) digits is 324, while the sum is 18.

Adding to 21003312330 its reverse (3321330012), we get a palindrome (24324642342).

It can be divided in two parts, 21003 and 312330, that added together give a palindrome (333333).

The spelling of 21003312330 in words is "twenty-one billion, three million, three hundred twelve thousand, three hundred thirty".