65540065 has 16 divisors (see below), whose sum is σ = 80902800. Its totient is φ = 50948352.

The previous prime is 65540039. The next prime is 65540089. The reversal of 65540065 is 56004556.

It can be written as a sum of positive squares in 8 ways, for example, as 1347921 + 64192144 = 1161^2 + 8012^2 .

It is a cyclic number.

It is not a de Polignac number, because 65540065 - 2²⁵ = 31985633 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 27751 + ... + 30019.

It is an arithmetic number, because the mean of its divisors is an integer number (5056425).

Almost surely, 2^65540065 is an apocalyptic number.

It is an amenable number.

65540065 is a deficient number, since it is larger than the sum of its proper divisors (15362735).

65540065 is a wasteful number, since it uses less digits than its factorization.

65540065 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2436.

The product of its (nonzero) digits is 18000, while the sum is 31.

The square root of 65540065 is about 8095.6818736904. The cubic root of 65540065 is about 403.1830716974.

The spelling of 65540065 in words is "sixty-five million, five hundred forty thousand, sixty-five".