221020325 has 18 divisors (see below), whose sum is σ = 276585906. Its totient is φ = 175203040.

The previous prime is 221020321. The next prime is 221020333. The reversal of 221020325 is 523020122.

It can be written as a sum of positive squares in 3 ways, for example, as 111556 + 220908769 = 334^2 + 14863^2 .

It is not a de Polignac number, because 221020325 - 2² = 221020321 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221020321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 697067 + ... + 697383.

Almost surely, 2^221020325 is an apocalyptic number.

221020325 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

221020325 is a deficient number, since it is larger than the sum of its proper divisors (55565581).

221020325 is an equidigital number, since it uses as much as digits as its factorization.

221020325 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 661 (or 489 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 17.

The square root of 221020325 is about 14866.7523353287. The cubic root of 221020325 is about 604.6128935434.

Adding to 221020325 its reverse (523020122), we get a palindrome (744040447).

The spelling of 221020325 in words is "two hundred twenty-one million, twenty thousand, three hundred twenty-five".