11815640 has 32 divisors (see below), whose sum is σ = 26892000. Its totient is φ = 4671744.

The previous prime is 11815633. The next prime is 11815649. The reversal of 11815640 is 4651811.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11815649) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1901 + ... + 5219.

It is an arithmetic number, because the mean of its divisors is an integer number (840375).

Almost surely, 2^11815640 is an apocalyptic number.

11815640 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 11815640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (13446000).

11815640 is an abundant number, since it is smaller than the sum of its proper divisors (15076360).

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

11815640 is a wasteful number, since it uses less digits than its factorization.

11815640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3419 (or 3415 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 26.

The square root of 11815640 is about 3437.3885436476. The cubic root of 11815640 is about 227.7643507629.

The spelling of 11815640 in words is "eleven million, eight hundred fifteen thousand, six hundred forty".