66669879 has 8 divisors (see below), whose sum is σ = 93571840. Its totient is φ = 42107256.

The previous prime is 66669857. The next prime is 66669899. The reversal of 66669879 is 97896666.

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

It is not a de Polignac number, because 66669879 - 2⁷ = 66669751 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (57), and also a Moran number because the ratio is a prime number: 1169647 = 66669879 / (6 + 6 + 6 + 6 + 9 + 8 + 7 + 9).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66669839) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 584767 + ... + 584880.

It is an arithmetic number, because the mean of its divisors is an integer number (11696480).

Almost surely, 2^66669879 is an apocalyptic number.

66669879 is a deficient number, since it is larger than the sum of its proper divisors (26901961).

66669879 is a wasteful number, since it uses less digits than its factorization.

66669879 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1169669.

The product of its digits is 5878656, while the sum is 57.

The square root of 66669879 is about 8165.1625213464. The cubic root of 66669879 is about 405.4866456204.

The spelling of 66669879 in words is "sixty-six million, six hundred sixty-nine thousand, eight hundred seventy-nine".