66172783 has 4 divisors (see below), whose sum is σ = 66199888. Its totient is φ = 66145680.

The previous prime is 66172753. The next prime is 66172907. The reversal of 66172783 is 38727166.

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

It is a cyclic number.

It is not a de Polignac number, because 66172783 - 2¹³ = 66164591 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66172753) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9483 + ... + 14908.

It is an arithmetic number, because the mean of its divisors is an integer number (16549972).

Almost surely, 2^66172783 is an apocalyptic number.

66172783 is a deficient number, since it is larger than the sum of its proper divisors (27105).

66172783 is a wasteful number, since it uses less digits than its factorization.

66172783 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27104.

The product of its digits is 84672, while the sum is 40.

The square root of 66172783 is about 8134.6655124842. The cubic root of 66172783 is about 404.4763501080.

The spelling of 66172783 in words is "sixty-six million, one hundred seventy-two thousand, seven hundred eighty-three".