65665261 has 4 divisors (see below), whose sum is σ = 65822400. Its totient is φ = 65508124.

The previous prime is 65665247. The next prime is 65665267. The reversal of 65665261 is 16256656.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 65665261 - 2⁷ = 65665133 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 65665261.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (65665267) 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, 77941 + ... + 78778.

It is an arithmetic number, because the mean of its divisors is an integer number (16455600).

Almost surely, 2^65665261 is an apocalyptic number.

It is an amenable number.

65665261 is a deficient number, since it is larger than the sum of its proper divisors (157139).

65665261 is a wasteful number, since it uses less digits than its factorization.

65665261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 157138.

The product of its digits is 64800, while the sum is 37.

The square root of 65665261 is about 8103.4104548641. The cubic root of 65665261 is about 403.4396313109.

The spelling of 65665261 in words is "sixty-five million, six hundred sixty-five thousand, two hundred sixty-one".