2139840 has 84 divisors (see below), whose sum is σ = 7370064. Its totient is φ = 569856.

The previous prime is 2139829. The next prime is 2139857. The reversal of 2139840 is 489312.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2509 + ... + 3251.

2^2139840 is an apocalyptic number.

2139840 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 2139840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3685032).

2139840 is an abundant number, since it is smaller than the sum of its proper divisors (5230224).

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

2139840 is a wasteful number, since it uses less digits than its factorization.

2139840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 766 (or 753 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 27.

The square root of 2139840 is about 1462.8191959364. The cubic root of 2139840 is about 128.8626625636.

The spelling of 2139840 in words is "two million, one hundred thirty-nine thousand, eight hundred forty".