221424425 has 12 divisors (see below), whose sum is σ = 284035020. Its totient is φ = 171030720.

The previous prime is 221424377. The next prime is 221424431. The reversal of 221424425 is 524424122.

221424425 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 6 ways, for example, as 32444416 + 188980009 = 5696^2 + 13747^2 .

It is not a de Polignac number, because 221424425 - 2¹⁸ = 221162281 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 221424394 and 221424403.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 151982 + ... + 153431.

It is an arithmetic number, because the mean of its divisors is an integer number (23669585).

Almost surely, 2^221424425 is an apocalyptic number.

221424425 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

221424425 is a deficient number, since it is larger than the sum of its proper divisors (62610595).

221424425 is a wasteful number, since it uses less digits than its factorization.

221424425 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 305452 (or 305447 counting only the distinct ones).

The product of its digits is 5120, while the sum is 26.

The square root of 221424425 is about 14880.3368577462. The cubic root of 221424425 is about 604.9811482412.

Adding to 221424425 its reverse (524424122), we get a palindrome (745848547).

The spelling of 221424425 in words is "two hundred twenty-one million, four hundred twenty-four thousand, four hundred twenty-five".