221443425 has 72 divisors (see below), whose sum is σ = 473076864. Its totient is φ = 96814080.

The previous prime is 221443403. The next prime is 221443427. The reversal of 221443425 is 524344122.

221443425 is a `hidden beast` number, since 221 + 4 + 434 + 2 + 5 = 666.

It is not a de Polignac number, because 221443425 - 2⁶ = 221443361 is a prime.

It is not an unprimeable number, because it can be changed into a prime (221443427) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 33169 + ... + 39281.

It is an arithmetic number, because the mean of its divisors is an integer number (6570512).

Almost surely, 2^221443425 is an apocalyptic number.

221443425 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

221443425 is an abundant number, since it is smaller than the sum of its proper divisors (251633439).

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

221443425 is a wasteful number, since it uses less digits than its factorization.

221443425 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6159 (or 6151 counting only the distinct ones).

The product of its digits is 7680, while the sum is 27.

The square root of 221443425 is about 14880.9752704586. The cubic root of 221443425 is about 604.9984518322.

Adding to 221443425 its reverse (524344122), we get a palindrome (745787547).

The spelling of 221443425 in words is "two hundred twenty-one million, four hundred forty-three thousand, four hundred twenty-five".