66331765 has 4 divisors (see below), whose sum is σ = 79598124. Its totient is φ = 53065408.

The previous prime is 66331751. The next prime is 66331813. The reversal of 66331765 is 56713366.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 22335076 + 43996689 = 4726^2 + 6633^2 .

It is a cyclic number.

It is not a de Polignac number, because 66331765 - 2¹¹ = 66329717 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6633172 + ... + 6633181.

It is an arithmetic number, because the mean of its divisors is an integer number (19899531).

Almost surely, 2^66331765 is an apocalyptic number.

It is an amenable number.

66331765 is a deficient number, since it is larger than the sum of its proper divisors (13266359).

66331765 is a wasteful number, since it uses less digits than its factorization.

66331765 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13266358.

The product of its digits is 68040, while the sum is 37.

The square root of 66331765 is about 8144.4315332625. The cubic root of 66331765 is about 404.8000130353.

The spelling of 66331765 in words is "sixty-six million, three hundred thirty-one thousand, seven hundred sixty-five".