66780387 has 6 divisors (see below), whose sum is σ = 96460572. Its totient is φ = 44520252.

The previous prime is 66780379. The next prime is 66780443. The reversal of 66780387 is 78308766.

It is not a de Polignac number, because 66780387 - 2³ = 66780379 is a prime.

It is not an unprimeable number, because it can be changed into a prime (66780317) 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 5 ways as a sum of consecutive naturals, for example, 3710013 + ... + 3710030.

It is an arithmetic number, because the mean of its divisors is an integer number (16076762).

Almost surely, 2^66780387 is an apocalyptic number.

66780387 is a deficient number, since it is larger than the sum of its proper divisors (29680185).

66780387 is a wasteful number, since it uses less digits than its factorization.

66780387 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7420049 (or 7420046 counting only the distinct ones).

The product of its (nonzero) digits is 338688, while the sum is 45.

The square root of 66780387 is about 8171.9267617864. The cubic root of 66780387 is about 405.7105587469.

The spelling of 66780387 in words is "sixty-six million, seven hundred eighty thousand, three hundred eighty-seven".