66065121 has 6 divisors (see below), whose sum is σ = 95427410. Its totient is φ = 44043408.

The previous prime is 66065107. The next prime is 66065173. The reversal of 66065121 is 12156066.

It is a happy number.

66065121 is a `hidden beast` number, since 6 + 6 + 0 + 651 + 2 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 53363025 + 12702096 = 7305^2 + 3564^2 .

It is a de Polignac number, because none of the positive numbers 2^k-66065121 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66060121) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 3670276 + ... + 3670293.

Almost surely, 2^66065121 is an apocalyptic number.

It is an amenable number.

66065121 is a deficient number, since it is larger than the sum of its proper divisors (29362289).

66065121 is a wasteful number, since it uses less digits than its factorization.

66065121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7340575 (or 7340572 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 27.

The square root of 66065121 is about 8128.0453369799. The cubic root of 66065121 is about 404.2568723066.

The spelling of 66065121 in words is "sixty-six million, sixty-five thousand, one hundred twenty-one".