221553425 has 6 divisors (see below), whose sum is σ = 274726278. Its totient is φ = 177242720.

The previous prime is 221553419. The next prime is 221553443. The reversal of 221553425 is 524355122.

It can be written as a sum of positive squares in 3 ways, for example, as 9443329 + 212110096 = 3073^2 + 14564^2 .

It is not a de Polignac number, because 221553425 - 2⁶ = 221553361 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4431044 + ... + 4431093.

It is an arithmetic number, because the mean of its divisors is an integer number (45787713).

Almost surely, 2^221553425 is an apocalyptic number.

221553425 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

221553425 is a deficient number, since it is larger than the sum of its proper divisors (53172853).

221553425 is an equidigital number, since it uses as much as digits as its factorization.

221553425 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8862147 (or 8862142 counting only the distinct ones).

The product of its digits is 12000, while the sum is 29.

The square root of 221553425 is about 14884.6708058996. The cubic root of 221553425 is about 605.0986110691.

The spelling of 221553425 in words is "two hundred twenty-one million, five hundred fifty-three thousand, four hundred twenty-five".