221668000 has 96 divisors (see below), whose sum is σ = 549739008. Its totient is φ = 87840000.

The previous prime is 221667983. The next prime is 221668001. The reversal of 221668000 is 866122.

It is a Harshad number since it is a multiple of its sum of digits (25).

It is not an unprimeable number, because it can be changed into a prime (221668001) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 603817 + ... + 604183.

It is an arithmetic number, because the mean of its divisors is an integer number (5726448).

Almost surely, 2^221668000 is an apocalyptic number.

221668000 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 221668000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (274869504).

221668000 is an abundant number, since it is smaller than the sum of its proper divisors (328071008).

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

221668000 is a wasteful number, since it uses less digits than its factorization.

221668000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 543 (or 525 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 25.

The square root of 221668000 is about 14888.5190667171. The cubic root of 221668000 is about 605.2029007767.

The spelling of 221668000 in words is "two hundred twenty-one million, six hundred sixty-eight thousand".