221066406 has 48 divisors (see below), whose sum is σ = 550031040. Its totient is φ = 63462960.

The previous prime is 221066399. The next prime is 221066441. The reversal of 221066406 is 604660122.

It is a happy number.

221066406 is a `hidden beast` number, since 2 + 2 + 10 + 6 + 640 + 6 = 666.

221066406 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a self number, because there is not a number n which added to its sum of digits gives 221066406.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 25620 + ... + 33143.

It is an arithmetic number, because the mean of its divisors is an integer number (11458980).

Almost surely, 2^221066406 is an apocalyptic number.

221066406 is an abundant number, since it is smaller than the sum of its proper divisors (328964634).

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

221066406 is a wasteful number, since it uses less digits than its factorization.

221066406 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 58801 (or 58798 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 27.

The square root of 221066406 is about 14868.3020550431. The cubic root of 221066406 is about 604.6549096351.

The spelling of 221066406 in words is "two hundred twenty-one million, sixty-six thousand, four hundred six".