66797783 has 4 divisors (see below), whose sum is σ = 71936088. Its totient is φ = 61659480.

The previous prime is 66797779. The next prime is 66797821. The reversal of 66797783 is 38779766.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 38779766 = 2 ⋅19389883.

It is a cyclic number.

It is not a de Polignac number, because 66797783 - 2² = 66797779 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 (66797713) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2569133 + ... + 2569158.

It is an arithmetic number, because the mean of its divisors is an integer number (17984022).

Almost surely, 2^66797783 is an apocalyptic number.

66797783 is a deficient number, since it is larger than the sum of its proper divisors (5138305).

66797783 is a wasteful number, since it uses less digits than its factorization.

66797783 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5138304.

The product of its digits is 2667168, while the sum is 53.

The square root of 66797783 is about 8172.9910681463. The cubic root of 66797783 is about 405.7457842996.

The spelling of 66797783 in words is "sixty-six million, seven hundred ninety-seven thousand, seven hundred eighty-three".