66782811 has 8 divisors (see below), whose sum is σ = 89144320. Its totient is φ = 44471592.

The previous prime is 66782791. The next prime is 66782819. The reversal of 66782811 is 11828766.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 66782811 - 2¹³ = 66774619 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 66782811.

It is not an unprimeable number, because it can be changed into a prime (66782819) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9355 + ... + 14868.

It is an arithmetic number, because the mean of its divisors is an integer number (11143040).

Almost surely, 2^66782811 is an apocalyptic number.

66782811 is a deficient number, since it is larger than the sum of its proper divisors (22361509).

66782811 is a wasteful number, since it uses less digits than its factorization.

66782811 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25145.

The product of its digits is 32256, while the sum is 39.

The square root of 66782811 is about 8172.0750730766. The cubic root of 66782811 is about 405.7154675259.

The spelling of 66782811 in words is "sixty-six million, seven hundred eighty-two thousand, eight hundred eleven".