221345306 has 32 divisors (see below), whose sum is σ = 418618368. Its totient is φ = 85426560.

The previous prime is 221345297. The next prime is 221345317. The reversal of 221345306 is 603543122.

221345306 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (26).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7370 + ... + 22293.

It is an arithmetic number, because the mean of its divisors is an integer number (13081824).

Almost surely, 2^221345306 is an apocalyptic number.

221345306 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

221345306 is a deficient number, since it is larger than the sum of its proper divisors (197273062).

221345306 is a wasteful number, since it uses less digits than its factorization.

221345306 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29726.

The product of its (nonzero) digits is 4320, while the sum is 26.

The square root of 221345306 is about 14877.6781118560. The cubic root of 221345306 is about 604.9090827112.

Adding to 221345306 its reverse (603543122), we get a palindrome (824888428).

The spelling of 221345306 in words is "two hundred twenty-one million, three hundred forty-five thousand, three hundred six".