66250791 has 16 divisors (see below), whose sum is σ = 99364320. Its totient is φ = 44165736.

The previous prime is 66250753. The next prime is 66250801. The reversal of 66250791 is 19705266.

66250791 is a `hidden beast` number, since 6 + 62 + 507 + 91 = 666.

It is not a de Polignac number, because 66250791 - 2⁶ = 66250727 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66250721) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12960 + ... + 17333.

It is an arithmetic number, because the mean of its divisors is an integer number (6210270).

Almost surely, 2^66250791 is an apocalyptic number.

66250791 is a deficient number, since it is larger than the sum of its proper divisors (33113529).

66250791 is an frugal number, since it uses more digits than its factorization.

66250791 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30314 (or 30296 counting only the distinct ones).

The product of its (nonzero) digits is 22680, while the sum is 36.

The square root of 66250791 is about 8139.4588886486. The cubic root of 66250791 is about 404.6352271128.

The spelling of 66250791 in words is "sixty-six million, two hundred fifty thousand, seven hundred ninety-one".