225720363661 has 4 divisors (see below), whose sum is σ = 243083468572. Its totient is φ = 208357258752.

The previous prime is 225720363613. The next prime is 225720363683. The reversal of 225720363661 is 166363027522.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 166363027522 = 2 ⋅83181513761.

It can be written as a sum of positive squares in 2 ways, for example, as 109988406025 + 115731957636 = 331645^2 + 340194^2 .

It is a cyclic number.

It is not a de Polignac number, because 225720363661 - 2⁹ = 225720363149 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (225720360661) 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, 8681552436 + ... + 8681552461.

It is an arithmetic number, because the mean of its divisors is an integer number (60770867143).

Almost surely, 2^225720363661 is an apocalyptic number.

It is an amenable number.

225720363661 is a deficient number, since it is larger than the sum of its proper divisors (17363104911).

225720363661 is a wasteful number, since it uses less digits than its factorization.

225720363661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17363104910.

The product of its (nonzero) digits is 544320, while the sum is 43.

The spelling of 225720363661 in words is "two hundred twenty-five billion, seven hundred twenty million, three hundred sixty-three thousand, six hundred sixty-one".