221951216844 has 288 divisors, whose sum is σ = 711970197120. Its totient is φ = 56834555904.

The previous prime is 221951216821. The next prime is 221951216933. The reversal of 221951216844 is 448612159122.

221951216844 is a `hidden beast` number, since 22 + 19 + 512 + 1 + 68 + 44 = 666.

It is a super-3 number, since 3×221951216844³ (a number of 35 digits) contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 221951216844.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 9056992 + ... + 9081464.

It is an arithmetic number, because the mean of its divisors is an integer number (2472118740).

Almost surely, 2^221951216844 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 221951216844, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (355985098560).

221951216844 is an abundant number, since it is smaller than the sum of its proper divisors (490018980276).

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

221951216844 is a wasteful number, since it uses less digits than its factorization.

221951216844 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24609 (or 24604 counting only the distinct ones).

The product of its digits is 276480, while the sum is 45.

The spelling of 221951216844 in words is "two hundred twenty-one billion, nine hundred fifty-one million, two hundred sixteen thousand, eight hundred forty-four".