66690765 has 24 divisors (see below), whose sum is σ = 119328768. Its totient is φ = 34420320.

The previous prime is 66690763. The next prime is 66690769. The reversal of 66690765 is 56709666.

It is not a de Polignac number, because 66690765 - 2¹ = 66690763 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 66690765.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66690763) 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, 22509 + ... + 25298.

It is an arithmetic number, because the mean of its divisors is an integer number (4972032).

Almost surely, 2^66690765 is an apocalyptic number.

It is an amenable number.

66690765 is a deficient number, since it is larger than the sum of its proper divisors (52638003).

66690765 is a wasteful number, since it uses less digits than its factorization.

66690765 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47849 (or 47846 counting only the distinct ones).

The product of its (nonzero) digits is 408240, while the sum is 45.

The square root of 66690765 is about 8166.4413914507. The cubic root of 66690765 is about 405.5289841296.

The spelling of 66690765 in words is "sixty-six million, six hundred ninety thousand, seven hundred sixty-five".