221611443768 has 192 divisors, whose sum is σ = 716688816480. Its totient is φ = 60972825600.

The previous prime is 221611443731. The next prime is 221611443769. The reversal of 221611443768 is 867344116122.

221611443768 is a `hidden beast` number, since 2 + 21 + 611 + 4 + 4 + 3 + 7 + 6 + 8 = 666.

It is a super-2 number, since 2×221611443768² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221611443769) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 451630 + ... + 804482.

Almost surely, 2^221611443768 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 221611443768, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (358344408240).

221611443768 is an abundant number, since it is smaller than the sum of its proper divisors (495077372712).

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

221611443768 is a wasteful number, since it uses less digits than its factorization.

221611443768 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 352950 (or 352943 counting only the distinct ones).

The product of its digits is 387072, while the sum is 45.

The spelling of 221611443768 in words is "two hundred twenty-one billion, six hundred eleven million, four hundred forty-three thousand, seven hundred sixty-eight".