225105661 has 4 divisors (see below), whose sum is σ = 245569824. Its totient is φ = 204641500.

The previous prime is 225105641. The next prime is 225105679. The reversal of 225105661 is 166501522.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-225105661 is a prime.

It is a super-2 number, since 2×225105661² = 101345117228493842, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (225105611) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10232065 + ... + 10232086.

It is an arithmetic number, because the mean of its divisors is an integer number (61392456).

Almost surely, 2^225105661 is an apocalyptic number.

It is an amenable number.

225105661 is a deficient number, since it is larger than the sum of its proper divisors (20464163).

225105661 is a wasteful number, since it uses less digits than its factorization.

225105661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20464162.

The product of its (nonzero) digits is 3600, while the sum is 28.

The square root of 225105661 is about 15003.5216199398. The cubic root of 225105661 is about 608.3153922942.

The spelling of 225105661 in words is "two hundred twenty-five million, one hundred five thousand, six hundred sixty-one".