16221473856 has 448 divisors, whose sum is σ = 57351168000. Its totient is φ = 4395866112.

The previous prime is 16221473803. The next prime is 16221473857. The reversal of 16221473856 is 65837412261.

16221473856 is a `hidden beast` number, since 1 + 6 + 221 + 47 + 385 + 6 = 666.

It is a tau number, because it is divible by the number of its divisors (448).

It is not an unprimeable number, because it can be changed into a prime (16221473857) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 55363246 + ... + 55363538.

It is an arithmetic number, because the mean of its divisors is an integer number (128016000).

Almost surely, 2^16221473856 is an apocalyptic number.

16221473856 is a gapful number since it is divisible by the number (16) 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 16221473856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28675584000).

16221473856 is an abundant number, since it is smaller than the sum of its proper divisors (41129694144).

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

16221473856 is a wasteful number, since it uses less digits than its factorization.

16221473856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 543 (or 527 counting only the distinct ones).

The product of its digits is 483840, while the sum is 45.

The spelling of 16221473856 in words is "sixteen billion, two hundred twenty-one million, four hundred seventy-three thousand, eight hundred fifty-six".