6857440666 has 8 divisors (see below), whose sum is σ = 10287170964. Its totient is φ = 3428383680.

The previous prime is 6857440663. The next prime is 6857440729. The reversal of 6857440666 is 6660447586.

It can be written as a sum of positive squares in 2 ways, for example, as 6856668025 + 772641 = 82805^2 + 879^2 .

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

It is not an unprimeable number, because it can be changed into a prime (6857440663) 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, 142045 + ... + 184096.

Almost surely, 2^6857440666 is an apocalyptic number.

6857440666 is a deficient number, since it is larger than the sum of its proper divisors (3429730298).

6857440666 is a wasteful number, since it uses less digits than its factorization.

6857440666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 336656.

The product of its (nonzero) digits is 5806080, while the sum is 52.

The square root of 6857440666 is about 82809.6652933702. The cubic root of 6857440666 is about 1899.8560062621.

The spelling of 6857440666 in words is "six billion, eight hundred fifty-seven million, four hundred forty thousand, six hundred sixty-six".