201561528545 has 8 divisors (see below), whose sum is σ = 260479513896. Its totient is φ = 148845436416.

The previous prime is 201561528451. The next prime is 201561528559. The reversal of 201561528545 is 545825165102.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 219069601 + 201342458944 = 14801^2 + 448712^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 201561528545 - 2³⁰ = 200487786721 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 201561528496 and 201561528505.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1550473232 + ... + 1550473361.

It is an arithmetic number, because the mean of its divisors is an integer number (32559939237).

Almost surely, 2^201561528545 is an apocalyptic number.

It is an amenable number.

201561528545 is a deficient number, since it is larger than the sum of its proper divisors (58917985351).

201561528545 is a wasteful number, since it uses less digits than its factorization.

201561528545 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3100946611.

The product of its (nonzero) digits is 480000, while the sum is 44.

The spelling of 201561528545 in words is "two hundred one billion, five hundred sixty-one million, five hundred twenty-eight thousand, five hundred forty-five".