221655563666440 has 192 divisors, whose sum is σ = 523857658383360. Its totient is φ = 84248919237120.

The previous prime is 221655563666413. The next prime is 221655563666483. The reversal of 221655563666440 is 44666365556122.

It is a super-3 number, since 3×221655563666440³ (a number of 44 digits) contains 333 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 34813184137 + ... + 34813190503.

It is an arithmetic number, because the mean of its divisors is an integer number (2728425304080).

Almost surely, 2^{221655563666440} is an apocalyptic number.

221655563666440 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 221655563666440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (261928829191680).

221655563666440 is an abundant number, since it is smaller than the sum of its proper divisors (302202094716920).

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

221655563666440 is a wasteful number, since it uses less digits than its factorization.

221655563666440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7940 (or 7757 counting only the distinct ones).

The product of its (nonzero) digits is 186624000, while the sum is 61.

The spelling of 221655563666440 in words is "two hundred twenty-one trillion, six hundred fifty-five billion, five hundred sixty-three million, six hundred sixty-six thousand, four hundred forty".