1666579378 has 8 divisors (see below), whose sum is σ = 2504264220. Its totient is φ = 831824640.

The previous prime is 1666579363. The next prime is 1666579393. The reversal of 1666579378 is 8739756661.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (1666579363) and next prime (1666579393).

It can be written as a sum of positive squares in 2 ways, for example, as 1250541769 + 416037609 = 35363^2 + 20397^2 .

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

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 731103 + ... + 733378.

Almost surely, 2^1666579378 is an apocalyptic number.

1666579378 is a deficient number, since it is larger than the sum of its proper divisors (837684842).

1666579378 is a wasteful number, since it uses less digits than its factorization.

1666579378 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1465052.

The product of its digits is 11430720, while the sum is 58.

The square root of 1666579378 is about 40823.7599689201. The cubic root of 1666579378 is about 1185.6104027037.

The spelling of 1666579378 in words is "one billion, six hundred sixty-six million, five hundred seventy-nine thousand, three hundred seventy-eight".