21521453541120 has 864 divisors, whose sum is σ = 85528025960832. Its totient is φ = 4949491580928.

The previous prime is 21521453541101. The next prime is 21521453541131. The reversal of 21521453541120 is 2114535412512.

21521453541120 is a `hidden beast` number, since 2 + 1 + 5 + 2 + 1 + 4 + 535 + 4 + 112 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

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, 348760189 + ... + 348821891.

It is an arithmetic number, because the mean of its divisors is an integer number (98990770788).

Almost surely, 2^{21521453541120} is an apocalyptic number.

21521453541120 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 21521453541120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42764012980416).

21521453541120 is an abundant number, since it is smaller than the sum of its proper divisors (64006572419712).

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

21521453541120 is a wasteful number, since it uses less digits than its factorization.

21521453541120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61897 (or 61880 counting only the distinct ones).

The product of its (nonzero) digits is 48000, while the sum is 36.

Adding to 21521453541120 its reverse (2114535412512), we get a palindrome (23635988953632).

The spelling of 21521453541120 in words is "twenty-one trillion, five hundred twenty-one billion, four hundred fifty-three million, five hundred forty-one thousand, one hundred twenty".