21121311330 has 240 divisors, whose sum is σ = 66271617720. Its totient is φ = 4812659712.

The previous prime is 21121311307. The next prime is 21121311359. The reversal of 21121311330 is 3311312112.

21121311330 is a `hidden beast` number, since 2 + 1 + 1 + 21 + 311 + 330 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 18637983441 + 2483327889 = 136521^2 + 49833^2 .

It is a super-2 number, since 2×21121311330² (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 119 ways as a sum of consecutive naturals, for example, 17185156 + ... + 17186384.

Almost surely, 2^21121311330 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21121311330, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33135808860).

21121311330 is an abundant number, since it is smaller than the sum of its proper divisors (45150306390).

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

21121311330 is a wasteful number, since it uses less digits than its factorization.

21121311330 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1695 (or 1679 counting only the distinct ones).

The product of its (nonzero) digits is 108, while the sum is 18.

Adding to 21121311330 its reverse (3311312112), we get a palindrome (24432623442).

The spelling of 21121311330 in words is "twenty-one billion, one hundred twenty-one million, three hundred eleven thousand, three hundred thirty".