11891520 has 84 divisors (see below), whose sum is σ = 40911780. Its totient is φ = 3170304.

The previous prime is 11891513. The next prime is 11891543. The reversal of 11891520 is 2519811.

It can be written as a sum of positive squares in 2 ways, for example, as 5419584 + 6471936 = 2328^2 + 2544^2 .

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 11 ways as a sum of consecutive naturals, for example, 816 + ... + 4944.

It is an arithmetic number, because the mean of its divisors is an integer number (487045).

Almost surely, 2^11891520 is an apocalyptic number.

11891520 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 11891520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (20455890).

11891520 is an abundant number, since it is smaller than the sum of its proper divisors (29020260).

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

11891520 is a wasteful number, since it uses less digits than its factorization.

11891520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4152 (or 4139 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 27.

The square root of 11891520 is about 3448.4083284901. The cubic root of 11891520 is about 228.2508780483.

The spelling of 11891520 in words is "eleven million, eight hundred ninety-one thousand, five hundred twenty".