221865978240 has 768 divisors, whose sum is σ = 835876454400. Its totient is φ = 54061793280.

The previous prime is 221865978227. The next prime is 221865978247. The reversal of 221865978240 is 42879568122.

221865978240 is a `hidden beast` number, since 2 + 2 + 1 + 8 + 6 + 597 + 8 + 2 + 40 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221865978247) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 365512017 + ... + 365512623.

It is an arithmetic number, because the mean of its divisors is an integer number (1088380800).

Almost surely, 2^221865978240 is an apocalyptic number.

221865978240 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 221865978240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (417938227200).

221865978240 is an abundant number, since it is smaller than the sum of its proper divisors (614010476160).

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

221865978240 is a wasteful number, since it uses less digits than its factorization.

221865978240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 775 (or 760 counting only the distinct ones).

The product of its (nonzero) digits is 3870720, while the sum is 54.

The spelling of 221865978240 in words is "two hundred twenty-one billion, eight hundred sixty-five million, nine hundred seventy-eight thousand, two hundred forty".