221145425 has 6 divisors (see below), whose sum is σ = 274220358. Its totient is φ = 176916320.

The previous prime is 221145377. The next prime is 221145439. The reversal of 221145425 is 524541122.

221145425 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 3 ways, for example, as 29931841 + 191213584 = 5471^2 + 13828^2 .

It is not a de Polignac number, because 221145425 - 2⁶ = 221145361 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 221145394 and 221145403.

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, 4422884 + ... + 4422933.

It is an arithmetic number, because the mean of its divisors is an integer number (45703393).

Almost surely, 2^221145425 is an apocalyptic number.

221145425 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

221145425 is a deficient number, since it is larger than the sum of its proper divisors (53074933).

221145425 is an equidigital number, since it uses as much as digits as its factorization.

221145425 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8845827 (or 8845822 counting only the distinct ones).

The product of its digits is 3200, while the sum is 26.

The square root of 221145425 is about 14870.9591149999. The cubic root of 221145425 is about 604.7269446033.

Adding to 221145425 its reverse (524541122), we get a palindrome (745686547).

The spelling of 221145425 in words is "two hundred twenty-one million, one hundred forty-five thousand, four hundred twenty-five".