1640866 has 8 divisors (see below), whose sum is σ = 2568384. Its totient is φ = 784740.

The previous prime is 1640851. The next prime is 1640869. The reversal of 1640866 is 6680461.

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 (1640869) 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, 17790 + ... + 17881.

It is an arithmetic number, because the mean of its divisors is an integer number (321048).

2^1640866 is an apocalyptic number.

1640866 is a deficient number, since it is larger than the sum of its proper divisors (927518).

1640866 is a wasteful number, since it uses less digits than its factorization.

1640866 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35696.

The product of its (nonzero) digits is 6912, while the sum is 31.

The square root of 1640866 is about 1280.9629190574. The cubic root of 1640866 is about 117.9481242817.

The spelling of 1640866 in words is "one million, six hundred forty thousand, eight hundred sixty-six".