221409006 has 128 divisors (see below), whose sum is σ = 572522496. Its totient is φ = 55520640.

The previous prime is 221408989. The next prime is 221409007. The reversal of 221409006 is 600904122.

221409006 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221409007) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1743315 + ... + 1743441.

It is an arithmetic number, because the mean of its divisors is an integer number (4472832).

Almost surely, 2^221409006 is an apocalyptic number.

221409006 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 221409006, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (286261248).

221409006 is an abundant number, since it is smaller than the sum of its proper divisors (351113490).

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

221409006 is a wasteful number, since it uses less digits than its factorization.

221409006 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 286.

The product of its (nonzero) digits is 864, while the sum is 24.

The square root of 221409006 is about 14879.8187488961. The cubic root of 221409006 is about 604.9671051942.

The spelling of 221409006 in words is "two hundred twenty-one million, four hundred nine thousand, six".