1640868 has 12 divisors (see below), whose sum is σ = 3828720. Its totient is φ = 546952.

The previous prime is 1640851. The next prime is 1640869. The reversal of 1640868 is 8680461.

It is a tau number, because it is divible by the number of its divisors (12).

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, 68358 + ... + 68381.

It is an arithmetic number, because the mean of its divisors is an integer number (319060).

2^1640868 is an apocalyptic number.

It is an amenable number.

1640868 is an abundant number, since it is smaller than the sum of its proper divisors (2187852).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1640868 is a wasteful number, since it uses less digits than its factorization.

1640868 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 136746 (or 136744 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 33.

The square root of 1640868 is about 1280.9636997199. The cubic root of 1640868 is about 117.9481722027.

The spelling of 1640868 in words is "one million, six hundred forty thousand, eight hundred sixty-eight".