225665691 has 4 divisors (see below), whose sum is σ = 300887592. Its totient is φ = 150443792.

The previous prime is 225665669. The next prime is 225665729. The reversal of 225665691 is 196566522.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 225665691 - 2¹¹ = 225663643 is a prime.

It is not an unprimeable number, because it can be changed into a prime (225665611) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 37610946 + ... + 37610951.

It is an arithmetic number, because the mean of its divisors is an integer number (75221898).

Almost surely, 2^225665691 is an apocalyptic number.

225665691 is a deficient number, since it is larger than the sum of its proper divisors (75221901).

225665691 is an equidigital number, since it uses as much as digits as its factorization.

225665691 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 75221900.

The product of its digits is 194400, while the sum is 42.

The square root of 225665691 is about 15022.1733114753. The cubic root of 225665691 is about 608.8194411352.

The spelling of 225665691 in words is "two hundred twenty-five million, six hundred sixty-five thousand, six hundred ninety-one".