21130109538720 has 576 divisors, whose sum is σ = 83913953429376. Its totient is φ = 4429814538240.

The previous prime is 21130109538709. The next prime is 21130109538803. The reversal of 21130109538720 is 2783590103112.

21130109538720 is digitally balanced in base 5, because in such base it contains all the possibile digits an equal number of times.

It is a super-3 number, since 3×21130109538720³ (a number of 41 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 47784235 + ... + 48224405.

It is an arithmetic number, because the mean of its divisors is an integer number (145683946926).

Almost surely, 2^{21130109538720} is an apocalyptic number.

21130109538720 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 21130109538720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (41956976714688).

21130109538720 is an abundant number, since it is smaller than the sum of its proper divisors (62783843890656).

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

21130109538720 is a wasteful number, since it uses less digits than its factorization.

21130109538720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 440373 (or 440358 counting only the distinct ones).

The product of its (nonzero) digits is 90720, while the sum is 42.

The spelling of 21130109538720 in words is "twenty-one trillion, one hundred thirty billion, one hundred nine million, five hundred thirty-eight thousand, seven hundred twenty".