1642840 has 32 divisors (see below), whose sum is σ = 3757680. Its totient is φ = 646272.

The previous prime is 1642831. The next prime is 1642843. The reversal of 1642840 is 482461.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1642843) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2374 + ... + 2986.

2^1642840 is an apocalyptic number.

1642840 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 1642840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1878840).

1642840 is an abundant number, since it is smaller than the sum of its proper divisors (2114840).

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

1642840 is a wasteful number, since it uses less digits than its factorization.

1642840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 691 (or 687 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 25.

The square root of 1642840 is about 1281.7332015673. The cubic root of 1642840 is about 117.9954034406.

The spelling of 1642840 in words is "one million, six hundred forty-two thousand, eight hundred forty".