221525545 has 8 divisors (see below), whose sum is σ = 265932360. Its totient is φ = 177152640.

The previous prime is 221525543. The next prime is 221525573. The reversal of 221525545 is 545525122.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 913936 + 220611609 = 956^2 + 14853^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 221525545 - 2¹ = 221525543 is a prime.

It is not an unprimeable number, because it can be changed into a prime (221525543) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9285 + ... + 23005.

It is an arithmetic number, because the mean of its divisors is an integer number (33241545).

Almost surely, 2^221525545 is an apocalyptic number.

It is an amenable number.

221525545 is a deficient number, since it is larger than the sum of its proper divisors (44406815).

221525545 is a wasteful number, since it uses less digits than its factorization.

221525545 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16955.

The product of its digits is 20000, while the sum is 31.

The square root of 221525545 is about 14883.7342424541. The cubic root of 221525545 is about 605.0732283923.

The spelling of 221525545 in words is "two hundred twenty-one million, five hundred twenty-five thousand, five hundred forty-five".