65205561 has 16 divisors (see below), whose sum is σ = 89092800. Its totient is φ = 42405888.

The previous prime is 65205527. The next prime is 65205577. The reversal of 65205561 is 16550256.

It is not a de Polignac number, because 65205561 - 2¹⁷ = 65074489 is a prime.

It is not an unprimeable number, because it can be changed into a prime (65205521) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 22905 + ... + 25593.

It is an arithmetic number, because the mean of its divisors is an integer number (5568300).

Almost surely, 2^65205561 is an apocalyptic number.

It is an amenable number.

65205561 is a deficient number, since it is larger than the sum of its proper divisors (23887239).

65205561 is a wasteful number, since it uses less digits than its factorization.

65205561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2888.

The product of its (nonzero) digits is 9000, while the sum is 30.

The square root of 65205561 is about 8074.9960371507. The cubic root of 65205561 is about 402.4959782528.

The spelling of 65205561 in words is "sixty-five million, two hundred five thousand, five hundred sixty-one".