2128640 has 36 divisors (see below), whose sum is σ = 5101824. Its totient is φ = 850944.

The previous prime is 2128631. The next prime is 2128649. The reversal of 2128640 is 468212.

It is an interprime number because it is at equal distance from previous prime (2128631) and next prime (2128649).

It is a super-2 number, since 2×2128640² = 9062216499200, which contains 22 as substring.

It is a hoax number, since the sum of its digits (23) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (2128649) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 449 + ... + 2111.

2^2128640 is an apocalyptic number.

2128640 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 2128640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2550912).

2128640 is an abundant number, since it is smaller than the sum of its proper divisors (2973184).

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

2128640 is an equidigital number, since it uses as much as digits as its factorization.

2128640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1684 (or 1670 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 23.

The square root of 2128640 is about 1458.9859492127. The cubic root of 2128640 is about 128.6374452270.

The spelling of 2128640 in words is "two million, one hundred twenty-eight thousand, six hundred forty".