1640240 has 80 divisors (see below), whose sum is σ = 4553280. Its totient is φ = 537600.

The previous prime is 1640231. The next prime is 1640263. The reversal of 1640240 is 420461.

It is a tau number, because it is divible by the number of its divisors (80).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16190 + ... + 16290.

It is an arithmetic number, because the mean of its divisors is an integer number (56916).

2^1640240 is an apocalyptic number.

1640240 is a gapful number since it is divisible by the number (10) 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 1640240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2276640).

1640240 is an abundant number, since it is smaller than the sum of its proper divisors (2913040).

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

1640240 is a wasteful number, since it uses less digits than its factorization.

1640240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 150 (or 144 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 17.

The square root of 1640240 is about 1280.7185483157. The cubic root of 1640240 is about 117.9331230735.

The spelling of 1640240 in words is "one million, six hundred forty thousand, two hundred forty".