208221025 has 6 divisors (see below), whose sum is σ = 258194102. Its totient is φ = 166576800.

The previous prime is 208220993. The next prime is 208221043. The reversal of 208221025 is 520122802.

It can be written as a sum of positive squares in 3 ways, for example, as 30558784 + 177662241 = 5528^2 + 13329^2 .

It is not a de Polignac number, because 208221025 - 2⁵ = 208220993 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 208220987 and 208221005.

It is an unprimeable number.

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 5 ways as a sum of consecutive naturals, for example, 4164396 + ... + 4164445.

Almost surely, 2^208221025 is an apocalyptic number.

208221025 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

208221025 is a deficient number, since it is larger than the sum of its proper divisors (49973077).

208221025 is an equidigital number, since it uses as much as digits as its factorization.

208221025 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8328851 (or 8328846 counting only the distinct ones).

The product of its (nonzero) digits is 640, while the sum is 22.

The square root of 208221025 is about 14429.8657304910. The cubic root of 208221025 is about 592.7090065984.

Adding to 208221025 its reverse (520122802), we get a palindrome (728343827).

The spelling of 208221025 in words is "two hundred eight million, two hundred twenty-one thousand, twenty-five".