11531520 has 432 divisors, whose sum is σ = 53569152. Its totient is φ = 2211840.

The previous prime is 11531519. The next prime is 11531521. The reversal of 11531520 is 2513511.

11531520 is a `hidden beast` number, since 115 + 31 + 520 = 666.

11531520 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (11531519) and next prime (11531521).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a zygodrome in base 4.

It is a junction number, because it is equal to n+sod(n) for n = 11531493 and 11531502.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11531521) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 887034 + ... + 887046.

Almost surely, 2^11531520 is an apocalyptic number.

11531520 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 11531520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26784576).

11531520 is an abundant number, since it is smaller than the sum of its proper divisors (42037632).

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

11531520 is a wasteful number, since it uses less digits than its factorization.

11531520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 58 (or 41 counting only the distinct ones).

The product of its (nonzero) digits is 150, while the sum is 18.

The square root of 11531520 is about 3395.8091819182. The cubic root of 11531520 is about 225.9239047334.

Subtracting from 11531520 its reverse (2513511), we obtain a square (9018009 = 3003²).

The spelling of 11531520 in words is "eleven million, five hundred thirty-one thousand, five hundred twenty".