221817964452 has 192 divisors, whose sum is σ = 687939194880. Its totient is φ = 54052061184.

The previous prime is 221817964451. The next prime is 221817964499. The reversal of 221817964452 is 254469718122.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (51).

It is a junction number, because it is equal to n+sod(n) for n = 221817964395 and 221817964404.

It is not an unprimeable number, because it can be changed into a prime (221817964451) 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, 446308 + ... + 801764.

It is an arithmetic number, because the mean of its divisors is an integer number (3583016640).

Almost surely, 2^221817964452 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 221817964452, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (343969597440).

221817964452 is an abundant number, since it is smaller than the sum of its proper divisors (466121230428).

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

221817964452 is a wasteful number, since it uses less digits than its factorization.

221817964452 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 355530 (or 355528 counting only the distinct ones).

The product of its digits is 1935360, while the sum is 51.

The spelling of 221817964452 in words is "two hundred twenty-one billion, eight hundred seventeen million, nine hundred sixty-four thousand, four hundred fifty-two".