21130525440 has 216 divisors, whose sum is σ = 73217551680. Its totient is φ = 5626478592.

The previous prime is 21130525439. The next prime is 21130525483. The reversal of 21130525440 is 4452503112.

21130525440 is a `hidden beast` number, since 2 + 1 + 130 + 525 + 4 + 4 + 0 = 666.

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 23 ways as a sum of consecutive naturals, for example, 14848569 + ... + 14849991.

Almost surely, 2^21130525440 is an apocalyptic number.

21130525440 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 21130525440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36608775840).

21130525440 is an abundant number, since it is smaller than the sum of its proper divisors (52087026240).

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

21130525440 is a wasteful number, since it uses less digits than its factorization.

21130525440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2739 (or 2722 counting only the distinct ones).

The product of its (nonzero) digits is 4800, while the sum is 27.

The spelling of 21130525440 in words is "twenty-one billion, one hundred thirty million, five hundred twenty-five thousand, four hundred forty".