221265625 has 63 divisors (see below), whose sum is σ = 341772969. Its totient is φ = 142800000.

The previous prime is 221265617. The next prime is 221265637. The reversal of 221265625 is 526562122.

It is a happy number.

The square root of 221265625 is 14875.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 10 ways, for example, as 217533001 + 3732624 = 14749^2 + 1932^2 .

It is not a de Polignac number, because 221265625 - 2³ = 221265617 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 62 ways as a sum of consecutive naturals, for example, 13015617 + ... + 13015633.

Almost surely, 2^221265625 is an apocalyptic number.

221265625 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

221265625 is the 14875-th square number.

221265625 is the 7438-th centered octagonal number.

It is an amenable number.

221265625 is a deficient number, since it is larger than the sum of its proper divisors (120507344).

221265625 is an frugal number, since it uses more digits than its factorization.

221265625 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 78 (or 29 counting only the distinct ones).

The product of its digits is 14400, while the sum is 31.

The cubic root of 221265625 is about 604.8364879249.

Multiplying 221265625 by its product of digits (14400), we get a square (3186225000000 = 1785000²).

The spelling of 221265625 in words is "two hundred twenty-one million, two hundred sixty-five thousand, six hundred twenty-five".