221791680 has 168 divisors, whose sum is σ = 832341744. Its totient is φ = 53760000.

The previous prime is 221791607. The next prime is 221791699. The reversal of 221791680 is 86197122.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 28180 + ... + 35180.

Almost surely, 2^221791680 is an apocalyptic number.

221791680 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 221791680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (416170872).

221791680 is an abundant number, since it is smaller than the sum of its proper divisors (610550064).

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

221791680 is a wasteful number, since it uses less digits than its factorization.

221791680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7035 (or 7022 counting only the distinct ones).

The product of its (nonzero) digits is 12096, while the sum is 36.

The square root of 221791680 is about 14892.6720235155. The cubic root of 221791680 is about 605.3154378110.

The spelling of 221791680 in words is "two hundred twenty-one million, seven hundred ninety-one thousand, six hundred eighty".