66065391 has 24 divisors (see below), whose sum is σ = 111724704. Its totient is φ = 36829440.

The previous prime is 66065381. The next prime is 66065423. The reversal of 66065391 is 19356066.

It is not a de Polignac number, because 66065391 - 2⁵ = 66065359 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66065341) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 10206 + ... + 15371.

It is an arithmetic number, because the mean of its divisors is an integer number (4655196).

Almost surely, 2^66065391 is an apocalyptic number.

66065391 is a deficient number, since it is larger than the sum of its proper divisors (45659313).

66065391 is a wasteful number, since it uses less digits than its factorization.

66065391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25631 (or 25628 counting only the distinct ones).

The product of its (nonzero) digits is 29160, while the sum is 36.

The square root of 66065391 is about 8128.0619461222. The cubic root of 66065391 is about 404.2574230219.

The spelling of 66065391 in words is "sixty-six million, sixty-five thousand, three hundred ninety-one".