11531540 has 12 divisors (see below), whose sum is σ = 24216276. Its totient is φ = 4612608.

The previous prime is 11531539. The next prime is 11531543. The reversal of 11531540 is 4513511.

It can be written as a sum of positive squares in 2 ways, for example, as 8305924 + 3225616 = 2882^2 + 1796^2 .

It is a Harshad number since it is a multiple of its sum of digits (20), and also a Moran number because the ratio is a prime number: 576577 = 11531540 / (1 + 1 + 5 + 3 + 1 + 5 + 4 + 0).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11531543) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 288269 + ... + 288308.

It is an arithmetic number, because the mean of its divisors is an integer number (2018023).

Almost surely, 2^11531540 is an apocalyptic number.

11531540 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

11531540 is an abundant number, since it is smaller than the sum of its proper divisors (12684736).

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

11531540 is a wasteful number, since it uses less digits than its factorization.

11531540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 576586 (or 576584 counting only the distinct ones).

The product of its (nonzero) digits is 300, while the sum is 20.

The square root of 11531540 is about 3395.8121267231. The cubic root of 11531540 is about 225.9240353457.

The spelling of 11531540 in words is "eleven million, five hundred thirty-one thousand, five hundred forty".