1640808 has 48 divisors (see below), whose sum is σ = 4788420. Its totient is φ = 504576.

The previous prime is 1640803. The next prime is 1640809. The reversal of 1640808 is 8080461.

It can be written as a sum of positive squares in 2 ways, for example, as 1258884 + 381924 = 1122^2 + 618^2 .

It is not an unprimeable number, because it can be changed into a prime (1640803) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 60 + ... + 1812.

2^1640808 is an apocalyptic number.

1640808 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1640808, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2394210).

1640808 is an abundant number, since it is smaller than the sum of its proper divisors (3147612).

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

1640808 is a wasteful number, since it uses less digits than its factorization.

1640808 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1778 (or 1771 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 27.

The square root of 1640808 is about 1280.9402796384. The cubic root of 1640808 is about 117.9467345538.

The spelling of 1640808 in words is "one million, six hundred forty thousand, eight hundred eight".