2639840 has 48 divisors (see below), whose sum is σ = 7130592. Its totient is φ = 904704.

The previous prime is 2639827. The next prime is 2639863. The reversal of 2639840 is 489362.

It is a Harshad number since it is a multiple of its sum of digits (32).

It is a junction number, because it is equal to n+sod(n) for n = 2639797 and 2639806.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 59 + ... + 2298.

It is an arithmetic number, because the mean of its divisors is an integer number (148554).

2^2639840 is an apocalyptic number.

2639840 is a gapful number since it is divisible by the number (20) 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 2639840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3565296).

2639840 is an abundant number, since it is smaller than the sum of its proper divisors (4490752).

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

2639840 is a wasteful number, since it uses less digits than its factorization.

2639840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2379 (or 2371 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 32.

The square root of 2639840 is about 1624.7584435848. The cubic root of 2639840 is about 138.2056724536.

The spelling of 2639840 in words is "two million, six hundred thirty-nine thousand, eight hundred forty".