221578666140 has 192 divisors, whose sum is σ = 727563916800. Its totient is φ = 49889903616.

The previous prime is 221578666109. The next prime is 221578666147. The reversal of 221578666140 is 41666875122.

It is a self number, because there is not a number n which added to its sum of digits gives 221578666140.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221578666147) 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, 171999 + ... + 687561.

It is an arithmetic number, because the mean of its divisors is an integer number (3789395400).

Almost surely, 2^221578666140 is an apocalyptic number.

221578666140 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 221578666140, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (363781958400).

221578666140 is an abundant number, since it is smaller than the sum of its proper divisors (505985250660).

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

221578666140 is a wasteful number, since it uses less digits than its factorization.

221578666140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 515636 (or 515634 counting only the distinct ones).

The product of its (nonzero) digits is 967680, while the sum is 48.

The spelling of 221578666140 in words is "two hundred twenty-one billion, five hundred seventy-eight million, six hundred sixty-six thousand, one hundred forty".