21685421552130 has 1024 divisors, whose sum is σ = 73602116812800. Its totient is φ = 4490180158464.

The previous prime is 21685421552089. The next prime is 21685421552141. The reversal of 21685421552130 is 3125512458612.

21685421552130 is a `hidden beast` number, since 2 + 1 + 6 + 8 + 5 + 421 + 5 + 5 + 213 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 511 ways as a sum of consecutive naturals, for example, 5411882587 + ... + 5411886593.

It is an arithmetic number, because the mean of its divisors is an integer number (71877067200).

Almost surely, 2^{21685421552130} is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21685421552130, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36801058406400).

21685421552130 is an abundant number, since it is smaller than the sum of its proper divisors (51916695260670).

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

21685421552130 is a wasteful number, since it uses less digits than its factorization.

21685421552130 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4147 (or 4129 counting only the distinct ones).

The product of its (nonzero) digits is 576000, while the sum is 45.

The spelling of 21685421552130 in words is "twenty-one trillion, six hundred eighty-five billion, four hundred twenty-one million, five hundred fifty-two thousand, one hundred thirty".