66785623 has 2 divisors, whose sum is σ = 66785624. Its totient is φ = 66785622.

The previous prime is 66785611. The next prime is 66785651. The reversal of 66785623 is 32658766.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66785623 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 66785623.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66785603) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33392811 + 33392812.

It is an arithmetic number, because the mean of its divisors is an integer number (33392812).

Almost surely, 2^66785623 is an apocalyptic number.

66785623 is a deficient number, since it is larger than the sum of its proper divisors (1).

66785623 is an equidigital number, since it uses as much as digits as its factorization.

66785623 is an evil number, because the sum of its binary digits is even.

The product of its digits is 362880, while the sum is 43.

The square root of 66785623 is about 8172.2471205905. The cubic root of 66785623 is about 405.7211618848.

The spelling of 66785623 in words is "sixty-six million, seven hundred eighty-five thousand, six hundred twenty-three".