21473686560 has 96 divisors (see below), whose sum is σ = 67778424000. Its totient is φ = 5714777088.

The previous prime is 21473686511. The next prime is 21473686571. The reversal of 21473686560 is 6568637412.

It is a tau number, because it is divible by the number of its divisors (96).

It is a super-2 number, since 2×21473686560² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 194694 + ... + 284346.

It is an arithmetic number, because the mean of its divisors is an integer number (706025250).

Almost surely, 2^21473686560 is an apocalyptic number.

21473686560 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 21473686560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33889212000).

21473686560 is an abundant number, since it is smaller than the sum of its proper divisors (46304737440).

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

21473686560 is a wasteful number, since it uses less digits than its factorization.

21473686560 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 90170 (or 90162 counting only the distinct ones).

The product of its (nonzero) digits is 1451520, while the sum is 48.

The spelling of 21473686560 in words is "twenty-one billion, four hundred seventy-three million, six hundred eighty-six thousand, five hundred sixty".