4000000666 has 4 divisors (see below), whose sum is σ = 6000001002. Its totient is φ = 2000000332.

The previous prime is 4000000663. The next prime is 4000000687. The reversal of 4000000666 is 6660000004.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 3046488025 + 953512641 = 55195^2 + 30879^2 .

4000000666 is a modest number, since divided by 666 gives 4 as remainder.

It is not an unprimeable number, because it can be changed into a prime (4000000661) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1000000165 + ... + 1000000168.

Almost surely, 2^4000000666 is an apocalyptic number.

4000000666 is a deficient number, since it is larger than the sum of its proper divisors (2000000336).

4000000666 is a wasteful number, since it uses less digits than its factorization.

4000000666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2000000335.

The product of its (nonzero) digits is 864, while the sum is 22.

The square root of 4000000666 is about 63245.5584685597. The cubic root of 4000000666 is about 1587.4011400690.

The spelling of 4000000666 in words is "four billion, six hundred sixty-six", and thus it is an aban number.