666440654 has 12 divisors (see below), whose sum is σ = 1098801312. Its totient is φ = 302927460.

The previous prime is 666440653. The next prime is 666440657. The reversal of 666440654 is 456044666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666440651) 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 5 ways as a sum of consecutive naturals, for example, 1376702 + ... + 1377185.

It is an arithmetic number, because the mean of its divisors is an integer number (91566776).

Almost surely, 2^666440654 is an apocalyptic number.

666440654 is a deficient number, since it is larger than the sum of its proper divisors (432360658).

666440654 is a wasteful number, since it uses less digits than its factorization.

666440654 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2753911 (or 2753900 counting only the distinct ones).

The product of its (nonzero) digits is 414720, while the sum is 41.

The square root of 666440654 is about 25815.5118872356. The cubic root of 666440654 is about 873.4817334530.

The spelling of 666440654 in words is "six hundred sixty-six million, four hundred forty thousand, six hundred fifty-four".