204225531561 has 12 divisors (see below), whose sum is σ = 305164587780. Its totient is φ = 131455514400.

The previous prime is 204225531511. The next prime is 204225531577. The reversal of 204225531561 is 165135522402.

204225531561 is a `hidden beast` number, since 2 + 0 + 42 + 2 + 5 + 53 + 1 + 561 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 132318427536 + 71907104025 = 363756^2 + 268155^2 .

It is not a de Polignac number, because 204225531561 - 2¹⁵ = 204225498793 is a prime.

It is not an unprimeable number, because it can be changed into a prime (204225531511) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 391236390 + ... + 391236911.

It is an arithmetic number, because the mean of its divisors is an integer number (25430382315).

Almost surely, 2^204225531561 is an apocalyptic number.

It is an amenable number.

204225531561 is a deficient number, since it is larger than the sum of its proper divisors (100939056219).

204225531561 is a wasteful number, since it uses less digits than its factorization.

204225531561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 782473336 (or 782473333 counting only the distinct ones).

The product of its (nonzero) digits is 72000, while the sum is 36.

The spelling of 204225531561 in words is "two hundred four billion, two hundred twenty-five million, five hundred thirty-one thousand, five hundred sixty-one".