21130668 has 72 divisors (see below), whose sum is σ = 58084208. Its totient is φ = 6438528.

The previous prime is 21130667. The next prime is 21130699. The reversal of 21130668 is 86603112.

It is not an unprimeable number, because it can be changed into a prime (21130667) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 76146 + ... + 76422.

Almost surely, 2^21130668 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21130668, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29042104).

21130668 is an abundant number, since it is smaller than the sum of its proper divisors (36953540).

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

21130668 is a wasteful number, since it uses less digits than its factorization.

21130668 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 463 (or 458 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 27.

The square root of 21130668 is about 4596.8106334719. The cubic root of 21130668 is about 276.4634620200.

The spelling of 21130668 in words is "twenty-one million, one hundred thirty thousand, six hundred sixty-eight".