66780479 has 4 divisors (see below), whose sum is σ = 68934720. Its totient is φ = 64626240.

The previous prime is 66780463. The next prime is 66780481. The reversal of 66780479 is 97408766.

It is a happy number.

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 66780479 - 2⁴ = 66780463 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 (66780379) 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, 1077074 + ... + 1077135.

It is an arithmetic number, because the mean of its divisors is an integer number (17233680).

Almost surely, 2^66780479 is an apocalyptic number.

66780479 is a deficient number, since it is larger than the sum of its proper divisors (2154241).

66780479 is a wasteful number, since it uses less digits than its factorization.

66780479 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2154240.

The product of its (nonzero) digits is 508032, while the sum is 47.

The square root of 66780479 is about 8171.9323908119. The cubic root of 66780479 is about 405.7107450558.

The spelling of 66780479 in words is "sixty-six million, seven hundred eighty thousand, four hundred seventy-nine".