11871540 has 72 divisors (see below), whose sum is σ = 36422568. Its totient is φ = 3129600.

The previous prime is 11871511. The next prime is 11871551. The reversal of 11871540 is 4517811.

11871540 is a `hidden beast` number, since 118 + 7 + 1 + 540 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 2471184 + 9400356 = 1572^2 + 3066^2 .

It is a congruent number.

It is an unprimeable number.

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 23 ways as a sum of consecutive naturals, for example, 17854 + ... + 18506.

It is an arithmetic number, because the mean of its divisors is an integer number (505869).

Almost surely, 2^11871540 is an apocalyptic number.

11871540 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 11871540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (18211284).

11871540 is an abundant number, since it is smaller than the sum of its proper divisors (24551028).

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

11871540 is a wasteful number, since it uses less digits than its factorization.

11871540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 769 (or 764 counting only the distinct ones).

The product of its (nonzero) digits is 1120, while the sum is 27.

The square root of 11871540 is about 3445.5101218833. The cubic root of 11871540 is about 228.1229715213.

The spelling of 11871540 in words is "eleven million, eight hundred seventy-one thousand, five hundred forty".