221281208064 has 216 divisors, whose sum is σ = 733989215232. Its totient is φ = 62803814400.

The previous prime is 221281208051. The next prime is 221281208077. The reversal of 221281208064 is 460802182122.

221281208064 is a `hidden beast` number, since 221 + 281 + 20 + 80 + 64 = 666.

It is an interprime number because it is at equal distance from previous prime (221281208051) and next prime (221281208077).

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 23 ways as a sum of consecutive naturals, for example, 2389897 + ... + 2480759.

Almost surely, 2^221281208064 is an apocalyptic number.

221281208064 is a gapful number since it is divisible by the number (24) 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 221281208064, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (366994607616).

221281208064 is an abundant number, since it is smaller than the sum of its proper divisors (512708007168).

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

221281208064 is a wasteful number, since it uses less digits than its factorization.

221281208064 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 91043 (or 91026 counting only the distinct ones).

The product of its (nonzero) digits is 24576, while the sum is 36.

The spelling of 221281208064 in words is "two hundred twenty-one billion, two hundred eighty-one million, two hundred eight thousand, sixty-four".