21553494172560 has 480 divisors, whose sum is σ = 83136625558272. Its totient is φ = 4902003671040.

The previous prime is 21553494172559. The next prime is 21553494172607. The reversal of 21553494172560 is 6527149435512.

21553494172560 is a `hidden beast` number, since 2 + 1 + 5 + 5 + 3 + 4 + 9 + 4 + 1 + 72 + 560 = 666.

It is a super-2 number, since 2×21553494172560² (a number of 27 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21553494172497 and 21553494172506.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 1257708312 + ... + 1257725448.

Almost surely, 2^{21553494172560} is an apocalyptic number.

21553494172560 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 21553494172560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (41568312779136).

21553494172560 is an abundant number, since it is smaller than the sum of its proper divisors (61583131385712).

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

21553494172560 is a wasteful number, since it uses less digits than its factorization.

21553494172560 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18391 (or 18382 counting only the distinct ones).

The product of its (nonzero) digits is 9072000, while the sum is 54.

The spelling of 21553494172560 in words is "twenty-one trillion, five hundred fifty-three billion, four hundred ninety-four million, one hundred seventy-two thousand, five hundred sixty".