65666861 has 8 divisors (see below), whose sum is σ = 71571360. Its totient is φ = 59884272.

The previous prime is 65666857. The next prime is 65666873. The reversal of 65666861 is 16866656.

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 65666861 - 2² = 65666857 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (65666851) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 29351 + ... + 31508.

It is an arithmetic number, because the mean of its divisors is an integer number (8946420).

Almost surely, 2^65666861 is an apocalyptic number.

It is an amenable number.

65666861 is a deficient number, since it is larger than the sum of its proper divisors (5904499).

65666861 is a wasteful number, since it uses less digits than its factorization.

65666861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 60955.

The product of its digits is 311040, while the sum is 44.

The square root of 65666861 is about 8103.5091781277. The cubic root of 65666861 is about 403.4429080215.

The spelling of 65666861 in words is "sixty-five million, six hundred sixty-six thousand, eight hundred sixty-one".