65665791 has 12 divisors (see below), whose sum is σ = 94966560. Its totient is φ = 43723680.

The previous prime is 65665771. The next prime is 65665811. The reversal of 65665791 is 19756656.

It is an interprime number because it is at equal distance from previous prime (65665771) and next prime (65665811).

It is not a de Polignac number, because 65665791 - 2⁶ = 65665727 is a prime.

It is a super-2 number, since 2×65665791² = 8623992215311362, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (65665711) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4195 + ... + 12203.

It is an arithmetic number, because the mean of its divisors is an integer number (7913880).

Almost surely, 2^65665791 is an apocalyptic number.

65665791 is a deficient number, since it is larger than the sum of its proper divisors (29300769).

65665791 is a wasteful number, since it uses less digits than its factorization.

65665791 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8926 (or 8923 counting only the distinct ones).

The product of its digits is 340200, while the sum is 45.

The square root of 65665791 is about 8103.4431570784. The cubic root of 65665791 is about 403.4407167272.

It can be divided in two parts, 65 and 665791, that added together give a square (665856 = 816²).

The spelling of 65665791 in words is "sixty-five million, six hundred sixty-five thousand, seven hundred ninety-one".