66745665 has 24 divisors (see below), whose sum is σ = 132220608. Its totient is φ = 30512160.

The previous prime is 66745633. The next prime is 66745667. The reversal of 66745665 is 56654766.

It is not a de Polignac number, because 66745665 - 2⁵ = 66745633 is a prime.

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

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 66745665.

It is not an unprimeable number, because it can be changed into a prime (66745667) 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, 105631 + ... + 106260.

It is an arithmetic number, because the mean of its divisors is an integer number (5509192).

Almost surely, 2^66745665 is an apocalyptic number.

It is an amenable number.

66745665 is a deficient number, since it is larger than the sum of its proper divisors (65474943).

66745665 is a wasteful number, since it uses less digits than its factorization.

66745665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 211909 (or 211906 counting only the distinct ones).

The product of its digits is 907200, while the sum is 45.

The square root of 66745665 is about 8169.8020171850. The cubic root of 66745665 is about 405.6402310910.

The spelling of 66745665 in words is "sixty-six million, seven hundred forty-five thousand, six hundred sixty-five".