221865433920 has 336 divisors, whose sum is σ = 824355447552. Its totient is φ = 54444994560.

The previous prime is 221865433891. The next prime is 221865433949. The reversal of 221865433920 is 29334568122.

221865433920 is a `hidden beast` number, since 2 + 2 + 1 + 86 + 543 + 3 + 9 + 20 = 666.

It is an interprime number because it is at equal distance from previous prime (221865433891) and next prime (221865433949).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

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, 12383689 + ... + 12401591.

It is an arithmetic number, because the mean of its divisors is an integer number (2453438832).

Almost surely, 2^221865433920 is an apocalyptic number.

221865433920 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 221865433920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (412177723776).

221865433920 is an abundant number, since it is smaller than the sum of its proper divisors (602490013632).

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

221865433920 is a wasteful number, since it uses less digits than its factorization.

221865433920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18270 (or 18257 counting only the distinct ones).

The product of its (nonzero) digits is 622080, while the sum is 45.

The spelling of 221865433920 in words is "two hundred twenty-one billion, eight hundred sixty-five million, four hundred thirty-three thousand, nine hundred twenty".